| "GI Joe" Maesch(Gilgamesh, Antisaviour, MESSiah +1) — Gigamesh | Gigamesh | Stanislaw Lem | Protagonist of Gigamesh |
| @kins — The Demolished Man | The Demolished Man | Alfred Bester | supporting |
| 9A(Acting Emperor, No one, My successor +1) — Perhaps the Stars | Perhaps the Stars | Ada Palmer | Mental/communication channel monitor |
| A certain critic(member of the Academy, academician) — Rien du tout, ou la consequence | Rien du tout, ou la consequence | Stanislaw Lem | Literary critic |
| A certain mendicant — The Fifth Sally or The Mischief of King Balerion | The Fifth Sally or The Mischief of King Balerion | Stanislaw Lem | Beggar |
| A Christian — The Approach to Al-Mu'tasim | The Approach to Al-Mu'tasim | Jorge Luis Borges | Pilgrim |
| A librarian of genius(This philosopher) — The Library of Babel | The Library of Babel | Jorge Luis Borges | Historical scholar |
| A malka-sansi — The Approach to Al-Mu'tasim | The Approach to Al-Mu'tasim | Jorge Luis Borges | Woman of the caste of thieves |
| A red lama — The Approach to Al-Mu'tasim | The Approach to Al-Mu'tasim | Jorge Luis Borges | Pilgrim |
| A. Bettik — Hyperion | Hyperion | Dan Simmons | Android crew member |
| Aaor — Imago | Imago | Octavia E. Butler | Jodahs's ooloi sibling |
| Aaron — The Coral Bones | The Coral Bones | Jynne Martin | Colleague |
| Aaron Loewenthal(Loewenthal) — Tlön, Uqbar, Orbis Tertius | Tlön, Uqbar, Orbis Tertius | Jorge Luis Borges | Victim |
| Aaron Pursley(Pursley) — Virtual Light | Virtual Light | William Gibson | Lawyer |
| Abban — Cyteen | Cyteen | C. J. Cherryh | Giraud Nye's azi bodyguard and staffer |
| Abbot Arkos(Dom Arkos, AOL, Abbas, the abbot +2) — A Canticle for Leibowitz | A Canticle for Leibowitz | Walter M. Miller, Jr. | Authority figure/Opponent |
| Abbot Zerchi(Dom Jethrah Zerchi, Dom Zerchi, Domne +2) — A Canticle for Leibowitz | A Canticle for Leibowitz | Walter M. Miller, Jr. | actantial:subject |
| Abdul Hegazi(Hegazi) — Revelation Space | Revelation Space | Alastair Reynolds | Triumvir |
| Abe Moise — Starship Troopers | Starship Troopers | Robert A. Heinlein | minor |
| Abira — Adulthood Rites | Adulthood Rites | Octavia E. Butler | Resister |
| Academician A. Slysz(Slysz) — New Cosmogony | New Cosmogony | Stanislaw Lem | Academic author |
| Acceptor — Startide Rising | Startide Rising | David Brin | Tandu psychic client/adept |
| Ace — Starship Troopers | Starship Troopers | Robert A. Heinlein | Squad leader / peer advisor |
| Acheropoulos — A Perfect Vacuum | A Perfect Vacuum | Stanislaw Lem | Fictional physicist |
| Achilles(Achilles de Flandres, Achilles Flandres) — Ender's Game | Ender's Game | Orson Scott Card | Primary antagonist |
| Achilles(War Marshal, Ancile Breaker) — Perhaps the Stars | Perhaps the Stars | Ada Palmer | Orbital Commander |
| Achilles(Achilles son of Peleus, Major, King of the Myrmidons +5) — The Will to Battle | The Will to Battle | Ada Palmer | Resurrected ancient hero |
| ADAN 300 — A Perfect Vacuum | A Perfect Vacuum | Stanislaw Lem | Personoid |
| ADAN 300(ADAN) — Non Serviam | Non Serviam | Stanislaw Lem | Personoid philosopher / primary theodicy voice |
| Ade Tukunbo — Ancillary Sword | Ancillary Sword | Ann Leckie | navigator |
| Adele Elia — The Ministry for the Future | The Ministry for the Future | Kim Stanley Robinson | Glaciologist |
| Adesh Singh — Stories of Your Life and Others | Stories of Your Life and Others | Ted Chiang | 3rd-year student |
| Admiral Alvarez(Helene Alvarez) — The Uplift War | The Uplift War | David Brin | Human fleet admiral |
| Admiral Kanzian — Barrayar | Barrayar | Lois McMaster Bujold | actantial helper |
| Admiral Nashita — The Fall of Hyperion | The Fall of Hyperion | Dan Simmons | FORCE fleet commander |
| Admiral Singh(Singh, Kushwant Singh) — The Fall of Hyperion | The Fall of Hyperion | Dan Simmons | FORCE military commander in war council |
| ADNA — A Perfect Vacuum | A Perfect Vacuum | Stanislaw Lem | Personoid |
| ADNA — Non Serviam | Non Serviam | Stanislaw Lem | Personoid interlocutor |
| Adolf Alfred von Messen-Weydeneck zu Oryola und Münne-sacks, Baron Hamuras(Hamuras) — De Impossibilitate Vitae / De Impossibilitate Prognoscendi | De Impossibilitate Vitae / De Impossibilitate Prognoscendi | Stanislaw Lem | The nurse's first suitor |
| Adolfo Bioy Casares(Bioy) — Tlön, Uqbar, Orbis Tertius | Tlön, Uqbar, Orbis Tertius | Jorge Luis Borges | Friend/Collaborator |
| Adrienne — Blue Mars | Blue Mars | Kim Stanley Robinson | Helper / orientation guide |
| Adrienne — Red Mars | Red Mars | Kim Stanley Robinson | helper |
| AElius Lampridius — The Lottery in Babylon | The Lottery in Babylon | Jorge Luis Borges | Historian |
| Aesop Quarriman(Senator Quarriman, Chair Quarriman) — The Will to Battle | The Will to Battle | Ada Palmer | Chair of Esperanza City Games |
| Afram street man — Stand on Zanzibar | Stand on Zanzibar | John Brunner | Incidental antagonist |
| Agasu(Inky Jack, Hyacinth, Big One-Arm) — American Gods | American Gods | Neil Gaiman | historical interlude protagonist |
| Agnes — Doomsday Book | Doomsday Book | Connie Willis | Child of the medieval household |
| Agnes — Queen of the States | Queen of the States | Lisa Goldstein | Witness / secondary helper |
| Agnes Kilcannon(Mrs Kilcannon) — The Separation | The Separation | Christopher Priest | Tribunal member |
| Agni(Lord of the Fires, Lord Agni) — Lord of Light | Lord of Light | Roger Zelazny | opponent |
| Ahajas — Adulthood Rites | Adulthood Rites | Octavia E. Butler | Akin's Oankali mother |
| Ahajas — Dawn | Dawn | Octavia E. Butler | Oankali female |
| Ahajas — Imago | Imago | Octavia E. Butler | Oankali female parent |
| Ahuni — Stories of Your Life and Others | Stories of Your Life and Others | Ted Chiang | Miner |
| Ahuni — Tower of Babylon | Tower of Babylon | Ted Chiang | Elamite miner |
| Aikam Tsueh(Aikam, Tsueh) — The City & The City | The City & The City | China Miéville | Security guard |
| Ainsley Lowbeer(Inspector Lowbeer, Detective Inspector Ainsley Lowbeer, Adjustor +1) — Agency | Agency | William Gibson | Authority figure and orchestrator |
| Air-raid warden — Blackout/All Clear | Blackout/All Clear | Connie Willis | Minor antagonist / obstacle |
| Ajib(Ajib ibn Taher) — The Merchant and the Alchemist's Gate | The Merchant and the Alchemist's Gate | Ted Chiang | The Weaver Who Stole From Himself |
| Akbar — The Years of Rice and Salt | The Years of Rice and Salt | Kim Stanley Robinson | Actantial opponent / sender |
| Akin(kid, the boy, Eka) — Adulthood Rites | Adulthood Rites | Octavia E. Butler | Construct male and planetary restorer |
| Akin(the kid, the baby, Eka) — Imago | Imago | Octavia E. Butler | Construct male protagonist |
| Akjai — Adulthood Rites | Adulthood Rites | Octavia E. Butler | Ooloi teacher |
| Akkarat(Trade Minister) — The Windup Girl | The Windup Girl | Paolo Bacigalupi | Political antagonist / Trade Ministry faction leader |
| Akki — Startide Rising | Startide Rising | David Brin | Young neo-dolphin communications officer |
| Aknel Amnardbat — A Desolation Called Peace | A Desolation Called Peace | Arkady Martine | Councilor for Heritage, Lsel Station; antagonist |
| Al-Mu'tasim(He who goes in quest of aid) — The Approach to Al-Mu'tasim | The Approach to Al-Mu'tasim | Jorge Luis Borges | The Sought / Concept |
| Alabaster(the ten-ringer, 'Baster) — The Fifth Season | The Fifth Season | N.K. Jemisin | Powerful orogene partner to Syenite |
| Alabaster — The Stone Sky | The Stone Sky | N. K. Jemisin | absent presence |
| Alai(Caliph) — Ender's Game | Ender's Game | Orson Scott Card | Caliph / military leader / old friend |
| Alain — A Closed and Common Orbit | A Closed and Common Orbit | Becky Chambers | helper |
| Alain — Count Zero | Count Zero | William Gibson | Marly's ex-lover / Art dealer |
| Alan — Lost Futures | Lost Futures | Lisa Tuttle | Sophie's former lover |
| Alan Pace(Al) — The Sparrow | The Sparrow | Mary Doria Russell | Jesuit musicologist |
| Alastair Waynewright(A. Waynewright) — Being Inc. | Being Inc. | Stanislaw Lem | Author |
| Albert — Tlön, Uqbar, Orbis Tertius | Tlön, Uqbar, Orbis Tertius | Jorge Luis Borges | Scholar |
| Albert Speer(Herr Speer) — The Separation | The Separation | Christopher Priest | minor |
| Alberto Corrales — Spook Country | Spook Country | William Gibson | Locative artist |
| Aldrin — Too Like the Lightning | Too Like the Lightning | Ada Palmer | Nowhere child |
| Alejandro — Spook Country | Spook Country | William Gibson | Tito's relative and advisor |
| Alejandro Glencoe(don Alejandro) — The Circular Ruins | The Circular Ruins | Jorge Luis Borges | Chairman of the Congress |
| Alex — 2312 | 2312 | Kim Stanley Robinson | Deceased Orchestrator |
| Alex — Blue Mars | Blue Mars | Kim Stanley Robinson | Russian crew member |
| Alex — Dreamsnake | Dreamsnake | Vonda N. McIntyre | Jesse's partner / minor antagonist |
| Alex(African gray parrot) — The Great Silence | The Great Silence | Ted Chiang | Subject of cognitive research |
| Alex Bibescu — Liking What You See: A Documentary | Liking What You See: A Documentary | Ted Chiang | Professor of religious studies at Pembleton |
| Alex Bibescu — Stories of Your Life and Others | Stories of Your Life and Others | Ted Chiang | Professor of religious studies |
| Alexander Craggier(Narrator) — Tlön, Uqbar, Orbis Tertius | Tlön, Uqbar, Orbis Tertius | Jorge Luis Borges | Discoverer |
| Alexander Ferri(Ferri) — The Circular Ruins | The Circular Ruins | Jorge Luis Borges | Narrator and Congress delegate |
| Alexei(Brother Alexei, big boy) — Chasm City | Chasm City | Alastair Reynolds | Hostile Mendicant |
| Alf — Blackout/All Clear | Blackout/All Clear | Connie Willis | Evacuee child |
| Alfred Lanning(Dr. Lanning, Lanning) — I, Robot | I, Robot | Isaac Asimov | Director of Research, U.S. Robots |
| Alfred Vaz(Doc) — Rainbows End | Rainbows End | Vernor Vinge | Primary antagonist |
| Alfred Zellermann — Gruppenfuhrer Louis XVI | Gruppenfuhrer Louis XVI | Stanislaw Lem | Author of the reviewed novel |
| Ali(Mowlana) — The Years of Rice and Salt | The Years of Rice and Salt | Kim Stanley Robinson | Sufi master |
| Alia — Dune | Dune | Frank Herbert | actantial:subject |
| Alice(Alice Liddell, the Alice, the persona +3) — Take Back Plenty | Take Back Plenty | Colin Greenland | narrator/ship AI |
| Alice Gong Gu(Alice) — Rainbows End | Rainbows End | Vernor Vinge | supporting |
| Alice Hathaway — The Martian Chronicles | The Martian Chronicles | Ray Bradbury | Stranded colonist / physician-geologist |
| Alice Wood(Mistress Wood, Alice) — Queen of the States | Queen of the States | Lisa Goldstein | protagonist |
| Alison Shires — Idoru | Idoru | William Gibson | Slitscan target |
| Alitum — Stories of Your Life and Others | Stories of Your Life and Others | Ted Chiang | Kudda's wife |
| Alitum — Tower of Babylon | Tower of Babylon | Ted Chiang | Tower dweller |
| All-Powerful Disposer of Destiny(One in Three Persons, main computer, Tree of Knowledge) — Being Inc. | Being Inc. | Stanislaw Lem | Omnipotent AI System |
| Allison Zeigler(Allison) — Dawn | Dawn | Octavia E. Butler | Human survivor |
| Alma — The Handmaid's Tale | The Handmaid's Tale | Margaret Atwood | Handmaid at Birth Day |
| Alpha — Hyperion | Hyperion | Dan Simmons | Bikura leader |
| Alsever — The Forever War | The Forever War | Joe Haldeman | Doctor/officer |
| Alsrod(Thant Alsrod) — Stars in My Pocket Like Grains of Sand | Stars in My Pocket Like Grains of Sand | Samuel R. Delany | Guest/Acquaintance |
| Alter Litvak(Reb Litvak) — The Yiddish Policemen's Union | The Yiddish Policemen's Union | Michael Chabon | actantial:opponent/sender |
| Alvarez(Pimplehead) — The Moon Is a Harsh Mistress | The Moon Is a Harsh Mistress | Robert A. Heinlein | Authority security chief and antagonist |
| Alviss(Alviss son of Vindalf) — American Gods | American Gods | Neil Gaiman | minor deity |
| Amahain-Frolk — Ancillary Sword | Ancillary Sword | Ann Leckie | antagonist / authority figure |
| Amalfi Schwartz — Hyperion | Hyperion | Dan Simmons | Childhood friend of Silenus |
| Amanda Bates(Bates, Amanda, jarhead +4) — Blindsight | Blindsight | Peter Watts | Combat Specialist |
| Amarandina Cybernella(only daughter of the ruler of the neighboring state of lb, the Emperor's daughter) — The Fourth Sally or How Trurl Built a Femfatalatron | The Fourth Sally or How Trurl Built a Femfatalatron | Stanislaw Lem | Object of affection |
| Ambassador Bose(Dr Bose, His Excellency the Ambassador of Mars) — Rendezvous with Rama | Rendezvous with Rama | Arthur C. Clarke | Rama Committee chairman |
| Ambul — Ender's Game | Ender's Game | Orson Scott Card | Helper / intelligence asset |
| Amdi(Amdijefri, Amdiranifani, Puppies) — A Fire Upon the Deep | A Fire Upon the Deep | Vernor Vinge | actantial:helper |
| Amelia — Chasm City | Chasm City | Alastair Reynolds | Ice Mendicant and caretaker |
| Amelia(Blaze, Dr. Harding, Blaze Harding) — Forever Peace | Forever Peace | Joe Haldeman | Julian's lover, physicist |
| Amelia — New York 2140 | New York 2140 | Kim Stanley Robinson | Internet broadcaster and airship pilot |
| Amena — Network Effect | Network Effect | Martha Wells | Mensah's adolescent daughter / survey intern |
| Amihan(Ami) — The Coral Bones | The Coral Bones | Jynne Martin | Telma's surviving daughter |
| Amina — Echopraxia | Echopraxia | Peter Watts | Bicameral node |
| Amma — Adulthood Rites | Adulthood Rites | Octavia E. Butler | Construct child |
| Amma — Imago | Imago | Octavia E. Butler | Construct child / Captive |
| Amorim — Ficciones (Tlön, Uqbar, Orbis Tertius) | Ficciones (Tlön, Uqbar, Orbis Tertius) | Jorge Luis Borges | Narrator's companion |
| Amorim — Tlön, Uqbar, Orbis Tertius | Tlön, Uqbar, Orbis Tertius | Jorge Luis Borges | Companion |
| Amorphia(avatar) — Excession | Excession | Iain M. Banks | Avatar of the Sleeper Service |
| Amos Burton — Ancillary Sword | Ancillary Sword | Ann Leckie | engineer's assistant |
| Ampleforth — 1984 | 1984 | George Orwell | minor character |
| Amy Carnath(Sera Carnath, Sera Amy, Young Amy +1) — Cyteen | Cyteen | C. J. Cherryh | secondary character |
| An(Kai-hui's daughter, Han An) — Air | Air | Geoff Ryman | Minor village youth |
| Ana Alvarado(Ana) — Exhalation | Exhalation | Ted Chiang | Digient Trainer / Tester |
| Ana Alvarado(Ana) — The Lifecycle of Software Objects | The Lifecycle of Software Objects | Ted Chiang | Digient trainer and owner |
| Ana Kahn(Officer Kahn, Private Kahn) — Ammonite | Ammonite | Nicola Griffith | Mirror officer / fencer |
| Anaander Mianaai(the Lord of the Radch, Mianaai, the tyrant +3) — Ancillary Justice | Ancillary Justice | Ann Leckie | Ruler / antagonist |
| Anaander Mianaai(Lord of the Radch, the tyrant) — Ancillary Sword | Ancillary Sword | Ann Leckie | Antagonist / ruler |
| Anaplian — Use of Weapons | Use of Weapons | Iain M. Banks | Observer |
| Anatole Fauche — Les Robinsonades | Les Robinsonades | Stanislaw Lem | Critic |
| Anatoly Kerensky(Lieutenant Kerensky) — Redshirts | Redshirts | John Scalzi | Lieutenant, main character / kidnap target |
| Anatomy Lecturer — Exhalation | Exhalation | Ted Chiang | Teacher |
| Anderson(Anderson-sama, Mr. Lake, yang guizi +2) — The Windup Girl | The Windup Girl | Paolo Bacigalupi | AgriGen operative running cover factory |
| Andil — Hyperion | Hyperion | Dan Simmons | opponent |
| Andrea — Count Zero | Count Zero | William Gibson | Marly's friend |
| Andrei Volkov(Volkov) — Pattern Recognition | Pattern Recognition | William Gibson | Russian oligarch |
| Andrej — Perdido Street Station | Perdido Street Station | China Miéville | Bait |
| Andrew B. Cross — A Perfect Vacuum | A Perfect Vacuum | Stanislaw Lem | Gynecologist |
| Andrew B. Cross — Gigamesh | Gigamesh | Stanislaw Lem | Minor character in Gigamesh |
| Andrew Dahl(Andy, Dill (misnamed by Abernathy), Dahl) — Redshirts | Redshirts | John Scalzi | Protagonist, Ensign/xenobiologist |
| Andrews — Doomsday Book | Doomsday Book | Connie Willis | Helper/technician |
| Andy — Cyteen | Cyteen | C. J. Cherryh | minor helper |
| Andy Jahns — Blue Mars | Blue Mars | Kim Stanley Robinson | Corporate fixer / transnat lobbyist |
| Andy Jahns — Red Mars | Red Mars | Kim Stanley Robinson | opponent |
| Angel — Starship Troopers | Starship Troopers | Robert A. Heinlein | helper |
| Angel of the South(the Blue One, he clad all in blue) — Lord of Light | Lord of Light | Roger Zelazny | minor helper |
| Angel Rhea(Rhea, angel) — Count Zero | Count Zero | William Gibson | Associate of Two-a-Day / Rescuer |
| Angela — The Truth of Fact, the Truth of Feeling | The Truth of Fact, the Truth of Feeling | Ted Chiang | Narrator's Ex-wife |
| Angela Mitchell(Angie) — Mona Lisa Overdrive | Mona Lisa Overdrive | William Gibson | SimStim star |
| Anghelov(Sergeant Anghebov) — The Forever War | The Forever War | Joe Haldeman | Soldier/helper |
| Ann(Ann Clayborne) — Blue Mars | Blue Mars | Kim Stanley Robinson | Geologist and Red anti-terraforming advocate |
| Ann — Green Mars | Green Mars | Kim Stanley Robinson | Red ideologue, geologist, First Hundred |
| Ann Clayborne — Green Mars | Green Mars | Kim Stanley Robinson | First Hundred geologist / Red ideologue |
| Ann Clayborne(Ann) — Red Mars | Red Mars | Kim Stanley Robinson | Red geologist, anti-terraforming voice |
| Anne — Division by Zero | Division by Zero | Ted Chiang | Marlene's best friend |
| Anne(Fair Witness) — Stranger in a Strange Land | Stranger in a Strange Land | Robert A. Heinlein | Fair Witness and secretary |
| Anne Edwards(Mr. Edwards, George, Dr. Edwards +3) — The Sparrow | The Sparrow | Mary Doria Russell | Physician; skeptic and moral anchor of the group |
| Annika Lindstrom — Liking What You See: A Documentary | Liking What You See: A Documentary | Ted Chiang | 2nd-year student |
| Anonymoid(monster, pirate and a mage) — The Cyberiad | The Cyberiad | Stanislaw Lem | Cosmic Pirate |
| Anonymous(Comte Déguisé, Count Disguised) — Too Like the Lightning | Too Like the Lightning | Ada Palmer | Masked Noble |
| Antar — Green Mars | Green Mars | Kim Stanley Robinson | supporting |
| Anthea / the sisters(the aunts, his sisters) — Among Others | Among Others | Jo Walton | antagonist |
| Anthony — Ancillary Justice | Ancillary Justice | Ann Leckie | helper (Fortune's Pawn teaser) |
| Anthony(Anthony Drury) — Queen of the States | Queen of the States | Lisa Goldstein | Opponent / coin-debaser |
| Antimony(Stone eater) — The Fifth Season | The Fifth Season | N.K. Jemisin | Stone eater |
| Antique Dealer — Pattern Recognition | Pattern Recognition | William Gibson | Vendor |
| Anton(Professor Anton) — Ender's Game | Ender's Game | Orson Scott Card | Scientist / mentor surrogate |
| Anton — Liking What You See: A Documentary | Liking What You See: A Documentary | Ted Chiang | History of Ideas T.A. |
| Anton — Stories of Your Life and Others | Stories of Your Life and Others | Ted Chiang | Teaching Assistant |
| Antoninus Heliogabalus(Heliogabalus) — The Lottery in Babylon | The Lottery in Babylon | Jorge Luis Borges | Roman Emperor |
| Ao(old ragbag, old pothole) — Dreamsnake | Dreamsnake | Vonda N. McIntyre | secondary |
| Aoife — Ammonite | Ammonite | Nicola Griffith | Echraidhe tribeswoman / ward-keeper |
| Aozhani student (unnamed)(young woman) — The Years of Rice and Salt | The Years of Rice and Salt | Kim Stanley Robinson | Interlocutor |
| Apollo Mojave(Apollo) — Seven Surrenders | Seven Surrenders | Ada Palmer | Murdered Utopian |
| Apollo Mojave(Apollo) — The Will to Battle | The Will to Battle | Ada Palmer | Utopian commander |
| Appeal To Reason — Excession | Excession | Iain M. Banks | Zetetic Elench Ship |
| April — The Uplift War | The Uplift War | David Brin | Minor character / symbolic figure |
| April Wu(Sunshine, Pumpkin) — The Uplift War | The Uplift War | David Brin | Human child sheltered with the gorillas |
| Arada(Dr. Arada) — Network Effect | Network Effect | Martha Wells | Senior researcher / SecUnit's contracted supervisor |
| Aragh Chtel — A Desolation Called Peace | A Desolation Called Peace | Arkady Martine | minor |
| Aral(m'lord) — Barrayar | Barrayar | Lois McMaster Bujold | husband/regent |
| Archbishop Whitgift — Queen of the States | Queen of the States | Lisa Goldstein | Inquisitor |
| Archduke Ferdinand — De Impossibilitate Vitae / De Impossibilitate Prognoscendi | De Impossibilitate Vitae / De Impossibilitate Prognoscendi | Stanislaw Lem | Historical figure |
| Arevin — Dreamsnake | Dreamsnake | Vonda N. McIntyre | romantic interest / secondary protagonist |
| Argaven(the king, my lord) — The Left Hand of Darkness | The Left Hand of Darkness | Ursula K. Le Guin | opponent/authority |
| Argent Reivich(Reivich) — Chasm City | Chasm City | Alastair Reynolds | Assassination target |
| Arhys(Lord Arhys, Lord Arhys dy Lutez, Porifors +1) — Paladin of Souls | Paladin of Souls | Lois McMaster Bujold | actantial:helper |
| Ari(young Ari, Ariane Emory II, Ariane Emory +13) — Cyteen | Cyteen | C. J. Cherryh | Dominant political and scientific authority; Councillor of Science; director of Reseune |
| Ari Emory I(Sera, Ari) — Cyteen | Cyteen | C. J. Cherryh | Reseune director; antagonist |
| Ariadne — Green Mars | Green Mars | Kim Stanley Robinson | Dorsa Brevia contact |
| Arienrhod(the Snow Queen, the Winter Queen, Snow Queen +3) — The Snow Queen | The Snow Queen | Joan D. Vinge | Antagonist, genetic original |
| Aristides Acheropoulos — New Cosmogony | New Cosmogony | Stanislaw Lem | Philosopher of nature and author |
| Arkady — Blue Mars | Blue Mars | Kim Stanley Robinson | Russian provocateur and political radical |
| Arkady(Arkady Bogdanov, Arkady Nikelyovich) — Red Mars | Red Mars | Kim Stanley Robinson | Ideological provocateur, Phobos team leader |
| Arleigh McCrae(Arleigh) — Idoru | Idoru | William Gibson | Tech expert for Lo/Rez |
| Arly — Forever Peace | Forever Peace | Joe Haldeman | Platoon mechanic (incapacitated) |
| Armando(Mando) — New York 2140 | New York 2140 | Kim Stanley Robinson | Submarine services worker |
| Armitage(Mr. Who) — Neuromancer | Neuromancer | William Gibson | Mysterious employer |
| Arrad Tehemmy — The Left Hand of Darkness | The Left Hand of Darkness | Ursula K. Le Guin | helper |
| Arrow — Speaker for the Dead | Speaker for the Dead | Orson Scott Card | minor character |
| Art — Blue Mars | Blue Mars | Kim Stanley Robinson | Praxis representative and diplomatic facilitator |
| Art(Randolph) — Green Mars | Green Mars | Kim Stanley Robinson | Praxis recruit turned covert diplomat |
| Art — Red Mars | Red Mars | Kim Stanley Robinson | Praxis representative, diplomatic facilitator |
| ART(Perihelion, the hostile, targetted transport +1) — Network Effect | Network Effect | Martha Wells | Research transport / bot pilot AI / prior ally |
| Art Randolph(Arthur Randolph, Bear Man) — Blue Mars | Blue Mars | Kim Stanley Robinson | Protagonist / diplomatic facilitator |
| Art Randolph(Arthur Randolph, Bear Man, Ambassador to Mars) — Red Mars | Red Mars | Kim Stanley Robinson | protagonist |
| Arthur(Your Majesty, the king, Art +1) — Queen of the States | Queen of the States | Lisa Goldstein | Focal mystery / faerie prince |
| Arthur — Stand on Zanzibar | Stand on Zanzibar | John Brunner | Ideological interlocutor |
| Arthur H. — Never Let Me Go | Never Let Me Go | Kazuo Ishiguro | Hailsham student |
| Arthur Lawson — Omphalos | Omphalos | Ted Chiang | Astronomer |
| Arthur T. Mitford — To Say Nothing of the Dog | To Say Nothing of the Dog | Connie Willis | Minor train passenger |
| Asano Takumino Kami(lord of the castle of Ako) — The Form of the Sword | The Form of the Sword | Jorge Luis Borges | Disgraced lord |
| Ash — Agency | Agency | William Gibson | Future operative and IT specialist |
| Ash(Maria Anathema) — The Peripheral | The Peripheral | William Gibson | Lev's secretary / Assistant |
| Ashe(Ashe Foreth, Foreth rem ir Osboth) — The Left Hand of Darkness | The Left Hand of Darkness | Ursula K. Le Guin | Estraven's former kemmering |
| Asher — Forever Peace | Forever Peace | Joe Haldeman | helper/skeptic |
| Ashil — The City & The City | The City & The City | China Miéville | Avatar of Breach / Mentor |
| Askama — The Sparrow | The Sparrow | Mary Doria Russell | Young Runa child, Sandoz's first alien contact |
| Asra — The Left Hand of Darkness | The Left Hand of Darkness | Ursula K. Le Guin | minor character |
| Athaclena(Clennie, the General, the countess) — The Uplift War | The Uplift War | David Brin | Young Tymbrimi female, Uthacalthing's daughter |
| Atsula(the fox) — American Gods | American Gods | Neil Gaiman | historical interlude protagonist |
| Audrey Burton — American Gods | American Gods | Neil Gaiman | supporting |
| August(GY-7688) — Cyteen | Cyteen | C. J. Cherryh | minor/symbolic |
| Augustus Tate(Gus) — The Demolished Man | The Demolished Man | Alfred Bester | Helper/accomplice |
| Aunt Elizabeth — The Handmaid's Tale | The Handmaid's Tale | Margaret Atwood | Red Centre instructor presiding at birth |
| Aunt Esther(Esther Wexler, Miss Wexler) — The Calculating Stars | The Calculating Stars | Mary Robinette Kowal | helper |
| Aunt from the Hyperboreans(accoucheuse of the Hyperboreans) — Les Robinsonades | Les Robinsonades | Stanislaw Lem | Imaginary Relative |
| Aunt Lydia — The Handmaid's Tale | The Handmaid's Tale | Margaret Atwood | Indoctrination instructor at the Red Centre |
| Auntie Gwennie — Among Others | Among Others | Jo Walton | minor antagonist / comic figure |
| Auntie Teg — Among Others | Among Others | Jo Walton | helper / maternal figure |
| Australian — All Tomorrow's Parties | All Tomorrow's Parties | William Gibson | Investigator/Enforcer |
| Avelino Arredondo — The Form of the Sword | The Form of the Sword | Jorge Luis Borges | Clerk/Law student |
| Avelino Arredondo(Arredondo) — Tlön, Uqbar, Orbis Tertius | Tlön, Uqbar, Orbis Tertius | Jorge Luis Borges | Assassin |
| Awijan — The Sparrow | The Sparrow | Mary Doria Russell | Supaari's secretary/guide in Gayjur |
| Axel Borelius — Three Versions of Judas | Three Versions of Judas | Jorge Luis Borges | Theologian |
| Ayre — Adulthood Rites | Adulthood Rites | Octavia E. Butler | Oldest construct adult in Lo |
| Ayre — Dawn | Dawn | Octavia E. Butler | Lilith's deceased son |
| Ayre — Imago | Imago | Octavia E. Butler | Construct adult |
| Azagba(the legless zombie) — Echopraxia | Echopraxia | Peter Watts | Combat zombie |
| Azevedo Bandeira — The Form of the Sword | The Form of the Sword | Jorge Luis Borges | Boss |
| Azevedo Bandeira(Bandeira) — Tlön, Uqbar, Orbis Tertius | Tlön, Uqbar, Orbis Tertius | Jorge Luis Borges | Gang member / Victim |
| Aziz — Mirror Dance | Mirror Dance | Lois McMaster Bujold | Dendarii trooper (victim) |
| B — The Lottery in Babylon | The Lottery in Babylon | Jorge Luis Borges | Hypothetical individual |
| B. Frederick Judd — The Handmaid's Tale | The Handmaid's Tale | Margaret Atwood | Historical figure/Sons of Jacob architect |
| Badri — Blackout/All Clear | Blackout/All Clear | Connie Willis | Time-travel technician |
| Badri(the tech, Badri Chaudhuri, Mr. Chaudhuri) — Doomsday Book | Doomsday Book | Connie Willis | Incapacitated key witness |
| Bahram(Bahram al-Bokhara) — The Years of Rice and Salt | The Years of Rice and Salt | Kim Stanley Robinson | Merchant intermediary and household head |
| Bai — The Years of Rice and Salt | The Years of Rice and Salt | Kim Stanley Robinson | subject |
| Baine(Mr. Baine, William) — To Say Nothing of the Dog | To Say Nothing of the Dog | Connie Willis | Butler/love interest |
| Balerion(King of Cymberia, His Majesty, His Royal Highness) — The Fifth Sally or The Mischief of King Balerion | The Fifth Sally or The Mischief of King Balerion | Stanislaw Lem | Frivolous monarch who steals bodies |
| Baltazar(Thomas Bell, Tom Bell, Tommy Bell +1) — Lost Futures | Lost Futures | Lisa Tuttle | helper/love interest |
| Balthazar Plum(Balthazar dear) — Take Back Plenty | Take Back Plenty | Colin Greenland | minor |
| Balveda(Perosteck Balveda) — Ancillary Sword | Ancillary Sword | Ann Leckie | Culture agent / antagonist-helper |
| Banyat — The Windup Girl | The Windup Girl | Paolo Bacigalupi | Factory QA head |
| Bao(Bao Xinhua) — The Years of Rice and Salt | The Years of Rice and Salt | Kim Stanley Robinson | Teacher and narrative consciousness |
| Bao (aged) — The Years of Rice and Salt | The Years of Rice and Salt | Kim Stanley Robinson | narrator/teacher |
| Barakiel — Hell Is the Absence of God | Hell Is the Absence of God | Ted Chiang | Angel |
| Barbara D'Courtney(Baba) — The Demolished Man | The Demolished Man | Alfred Bester | Witness/victim |
| Barboo Seaves — Forever Peace | Forever Peace | Joe Haldeman | supporting |
| Bardiel — Hell Is the Absence of God | Hell Is the Absence of God | Ted Chiang | Angel |
| Barman — Pattern Recognition | Pattern Recognition | William Gibson | Informant/Footagehead |
| Baron Fell(Georish Stauber) — Mirror Dance | Mirror Dance | Lois McMaster Bujold | actantial helper (conditional) |
| Baron Römerstadt — The Secret Miracle | The Secret Miracle | Jorge Luis Borges | Character in play |
| Baron Ryoval(Ry Ryoval) — Mirror Dance | Mirror Dance | Lois McMaster Bujold | opponent |
| Baron Samedi — American Gods | American Gods | Neil Gaiman | actantial:helper |
| Baronne Lotus Bharaputra — Mirror Dance | Mirror Dance | Lois McMaster Bujold | exposition figure |
| Baronshteyn(Aryeh) — The Yiddish Policemen's Union | The Yiddish Policemen's Union | Michael Chabon | opponent/antagonist |
| Barry Larsen — Hell Is the Absence of God | Hell Is the Absence of God | Ted Chiang | Serial killer |
| Barry Silver — Lost Futures | Lost Futures | Lisa Tuttle | ex-boyfriend, alternate-world husband |
| Bartholocaust the Walleyed — The First Sally or The Trap of Gargantius | The First Sally or The Trap of Gargantius | Stanislaw Lem | Historical monarch |
| Bashaarat — Exhalation | Exhalation | Ted Chiang | Alchemist and Shopkeeper |
| Bashaarat(The shopkeeper) — The Merchant and the Alchemist's Gate | The Merchant and the Alchemist's Gate | Ted Chiang | Alchemist and Shopkeeper |
| Basiliscus — The Cyberiad | The Cyberiad | Stanislaw Lem | Constructor |
| Basiliscus the Gorgonite — The Third Sally or The Dragons of Probability | The Third Sally or The Dragons of Probability | Stanislaw Lem | Rogue constructor |
| Basira — The Calculating Stars | The Calculating Stars | Mary Robinette Kowal | supporting |
| Basnaaid Elming(Horticulturist Basnaaid, Horticulturist) — Ancillary Sword | Ancillary Sword | Ann Leckie | Horticulturist / sister of Lieutenant Awn |
| Bauber the Catalonian — Odysseus of Ithaca | Odysseus of Ithaca | Stanislaw Lem | Historical Genius |
| Bayonne — Starship Troopers | Starship Troopers | Robert A. Heinlein | minor |
| Baz Jesek(Commodore Jesek) — Mirror Dance | Mirror Dance | Lois McMaster Bujold | Fleet engineer |
| BB(Ernest) — Hyperion | Hyperion | Dan Simmons | Informant/cyberpuke civil servant |
| Bean(Julian Delphiki) — Ender's Game | Ender's Game | Orson Scott Card | Protagonist / former Hegemony commander |
| Bearded man(Ramone Alcin) — Spook Country | Spook Country | William Gibson | Truck Driver |
| Beatrice(Bea) — Lost Futures | Lost Futures | Lisa Tuttle | minor/helper |
| Beatrice(Beatrice Frost) — The Circular Ruins | The Circular Ruins | Jorge Luis Borges | Student and lover |
| Beatrice Dwyer(Beatrice) — Dawn | Dawn | Octavia E. Butler | Human survivor |
| Beatrice Dwyer(Beatrice) — Imago | Imago | Octavia E. Butler | Human survivor |
| Beatriz Viterbo(Beatriz Elena Viterbo) — The Form of the Sword | The Form of the Sword | Jorge Luis Borges | Deceased beloved |
| Beck(Jackson) — The Demolished Man | The Demolished Man | Alfred Bester | Powell's staff analyst |
| Bedap(Dap, Taddle Dap) — The Dispossessed | The Dispossessed | Ursula K. Le Guin | Syndicate member and Shevek's close friend |
| Beggar Man — Klara and the Sun | Klara and the Sun | Kazuo Ishiguro | Street dweller |
| Beie Chohooan — Startide Rising | Startide Rising | David Brin | Unknown alien observer (friendly) |
| Bel Thorne(Captain Thorne) — Mirror Dance | Mirror Dance | Lois McMaster Bujold | Helper / Unwitting accomplice |
| Belda — Forever Peace | Forever Peace | Joe Haldeman | helper |
| Beli — Tower of Babylon | Tower of Babylon | Ted Chiang | Foreman of the Elamite miners |
| Belinda — The Coral Bones | The Coral Bones | Jynne Martin | Maid/companion |
| Bella Lind(Bella) — Pushing Ice | Pushing Ice | Alastair Reynolds | Captain of Rockhopper |
| Ben Carter — The Peripheral | The Peripheral | William Gibson | Guard |
| Ben Caxton(Ben) — Stranger in a Strange Land | Stranger in a Strange Land | Robert A. Heinlein | convert/narrator-within-story |
| Ben Reich(Reich, Mac, Mr. Reich) — The Demolished Man | The Demolished Man | Alfred Bester | Protagonist/antagonist |
| Benito Taganes(Benny, Reb Taganes, donut king) — The Yiddish Policemen's Union | The Yiddish Policemen's Union | Michael Chabon | informant/helper |
| Benjamin(the Old Jew, the hermit, Old Jew +2) — A Canticle for Leibowitz | A Canticle for Leibowitz | Walter M. Miller, Jr. | actantial:helper / jung:trickster |
| Benjamin — The Uplift War | The Uplift War | David Brin | Helper / resistance lieutenant |
| Benjamin Driscoll(Mr. Benjamin Driscoll, Mr. Driscoll) — The Martian Chronicles | The Martian Chronicles | Ray Bradbury | protagonist |
| Benjamin Flex(Ben, Mr. Flex) — Perdido Street Station | Perdido Street Station | China Miéville | Editor of Runagate Rampant |
| Benjamín Otálora — The Form of the Sword | The Form of the Sword | Jorge Luis Borges | Usurper |
| Benjamín Otálora(Otálora) — Tlön, Uqbar, Orbis Tertius | Tlön, Uqbar, Orbis Tertius | Jorge Luis Borges | Usurper |
| Benjamin Roth(Roth) — Seventy-Two Letters | Seventy-Two Letters | Ted Chiang | Kabbalist |
| Benjamin Rubin(Benjamin P. Rubin) — Cyteen | Cyteen | C. J. Cherryh | Fargone chemist; newly designated Special |
| Benkoski(Wizard) — The Calculating Stars | The Calculating Stars | Mary Robinette Kowal | helper |
| Bennie Montez(Bernardo) — Starship Troopers | Starship Troopers | Robert A. Heinlein | minor character |
| Bennie Noakes — Stand on Zanzibar | Stand on Zanzibar | John Brunner | vignette figure |
| Benny Vasquez — Hell Is the Absence of God | Hell Is the Absence of God | Ted Chiang | Eyeless Devotee |
| Benyo — Forever Peace | Forever Peace | Joe Haldeman | helper |
| Berkina — Blue Mars | Blue Mars | Kim Stanley Robinson | Colleague |
| Berkina — Green Mars | Green Mars | Kim Stanley Robinson | Biotique scientist |
| Berkina — Red Mars | Red Mars | Kim Stanley Robinson | colleague / Biotique scientist |
| Bernard Carroway — Timescape | Timescape | Gregory Benford | Astrophysics colleague, committee member |
| Bernard de la Taille(shrewd Frenchman) — U-Write-It | U-Write-It | Stanislaw Lem | French author |
| Bernard Stonestreet(Bernard) — Pattern Recognition | Pattern Recognition | William Gibson | Blue Ant executive |
| Bernardo Haedo(young Bernardo Juan Francisco) — Funes the Memorious | Funes the Memorious | Jorge Luis Borges | The narrator's cousin |
| Berquist(Gil Berquist, Gilbert Berquist) — Stranger in a Strange Land | Stranger in a Strange Land | Robert A. Heinlein | Opponent / Government operative |
| Berry Rydell(Rydell, Nixon) — Virtual Light | Virtual Light | William Gibson | Unemployed armed-response driver |
| Berton — Solaris | Solaris | Stanislaw Lem | Pilot and Explorer |
| Bertrand — A Perfect Vacuum | A Perfect Vacuum | Stanislaw Lem | Hamlet figure |
| Bertrand Gülsenhirn(the Infante, Hamlet) — Gruppenfuhrer Louis XVI | Gruppenfuhrer Louis XVI | Stanislaw Lem | Taudlitz's nephew and heir |
| Beta — Hyperion | Hyperion | Dan Simmons | Bikura member |
| Betty — The Calculating Stars | The Calculating Stars | Mary Robinette Kowal | supporting |
| Bewt(el transportista de agua, Maestro Bewt) — Dune | Dune | Frank Herbert | opponent |
| Bhakta(Abbess Bhakta) — The Years of Rice and Salt | The Years of Rice and Salt | Kim Stanley Robinson | Buddhist abbess, host |
| Bible Peddler — Tlön, Uqbar, Orbis Tertius | Tlön, Uqbar, Orbis Tertius | Jorge Luis Borges | Salesman |
| Big Brother — 1984 | 1984 | George Orwell | symbolic figurehead |
| Biggs — The Martian Chronicles | The Martian Chronicles | Ray Bradbury | Crewman / catalyst |
| Bihari — The Years of Rice and Salt | The Years of Rice and Salt | Kim Stanley Robinson | Supporting |
| Bill Barbour(Barbour) — Do Androids Dream of Electric Sheep? | Do Androids Dream of Electric Sheep? | Philip K. Dick | minor |
| Bill Harrigan(Billy the Kid) — The Circular Ruins | The Circular Ruins | Jorge Luis Borges | Outlaw |
| Billy the Kid(Bill Harrigan) — Tlön, Uqbar, Orbis Tertius | Tlön, Uqbar, Orbis Tertius | Jorge Luis Borges | Outlaw |
| Bimniwha — The Stone Sky | The Stone Sky | N. K. Jemisin | helper (deep past) |
| Bina Gelbfish(Inspector Gelbfish, Bina, Gelbfish) — The Yiddish Policemen's Union | The Yiddish Policemen's Union | Michael Chabon | superior officer/antagonist-by-role |
| Binnie Hodbin(Spitfire) — Blackout/All Clear | Blackout/All Clear | Connie Willis | Supporting / evacuee child |
| Bioy Casares(Bioy) — Ficciones (Tlön, Uqbar, Orbis Tertius) | Ficciones (Tlön, Uqbar, Orbis Tertius) | Jorge Luis Borges | Narrator's friend |
| Birdie — Starship Troopers | Starship Troopers | Robert A. Heinlein | minor |
| Birgit — The Separation | The Separation | Christopher Priest | Host family member; later romantic interest of Joe |
| Bishop Oxtongue — Stranger in a Strange Land | Stranger in a Strange Land | Robert A. Heinlein | actantial:opponent |
| Bishop Peregrino(the Bishop) — Speaker for the Dead | Speaker for the Dead | Orson Scott Card | Religious authority |
| Bistami — The Years of Rice and Salt | The Years of Rice and Salt | Kim Stanley Robinson | Protagonist (Books 2–3 Sufi arc) |
| Black Finnegan — Death and the Compass | Death and the Compass | Jorge Luis Borges | Tavern owner |
| Black Finnegan(Finnegan) — The Form of the Sword | The Form of the Sword | Jorge Luis Borges | Tavern Owner |
| Black Jew from Cochin — The Approach to Al-Mu'tasim | The Approach to Al-Mu'tasim | Jorge Luis Borges | Pilgrim |
| Black Lars(Lars, Skern Black-lars) — Stars in My Pocket Like Grains of Sand | Stars in My Pocket Like Grains of Sand | Samuel R. Delany | Marq's sister |
| Black-and-white man — Klara and the Sun | Klara and the Sun | Kazuo Ishiguro | Petitioner |
| Blaisdell(General Blaisdell) — Forever Peace | Forever Peace | Joe Haldeman | opponent |
| Blind astrologer — The Approach to Al-Mu'tasim | The Approach to Al-Mu'tasim | Jorge Luis Borges | Minor Character |
| Bliss — Foundation's Edge | Foundation's Edge | Isaac Asimov | helper/messenger |
| Blodwed(TierPardée) — The Snow Queen | The Snow Queen | Joan D. Vinge | Nomad teenager / captor |
| Blond woman(Skull Wars woman) — Idoru | Idoru | William Gibson | Traveler / Smuggler associate |
| bloody rider — Tlön, Uqbar, Orbis Tertius | Tlön, Uqbar, Orbis Tertius | Jorge Luis Borges | Dying traveler |
| Blue — A Closed and Common Orbit | A Closed and Common Orbit | Becky Chambers | companion |
| Blueshell — A Fire Upon the Deep | A Fire Upon the Deep | Vernor Vinge | helper / actantial sender |
| Bo Chowdhury(Acting Commissioner General, Deputy Commissioner General, Deputy +1) — Perhaps the Stars | Perhaps the Stars | Ada Palmer | Acting Commissioner General |
| Bo Nine — Ancillary Sword | Ancillary Sword | Ann Leckie | Soldier, Breq's crew |
| Bob Gu(Lieutenant Colonel Robert Gu Jr., Bobby) — Rainbows End | Rainbows End | Vernor Vinge | Military authority/resolver |
| Bob Wharton — The Ministry for the Future | The Ministry for the Future | Kim Stanley Robinson | Scientist |
| Bobby(Count Zero, Count) — Count Zero | Count Zero | William Gibson | Console cowboy / Protagonist |
| Bobby Chombo(Bobby, Robert Fergusson, Shombo) — Spook Country | Spook Country | William Gibson | Locative tech-wonk / Hacker |
| Boer grandmother — The Diamond Age | The Diamond Age | Neal Stephenson | helper |
| Bogdanovitch — Cyteen | Cyteen | C. J. Cherryh | Council President; holder of Bureau of State seat |
| Bogle — The Form of the Sword | The Form of the Sword | Jorge Luis Borges | Genius |
| Bogle — Tlön, Uqbar, Orbis Tertius | Tlön, Uqbar, Orbis Tertius | Jorge Luis Borges | Supporter of an impostor |
| Bold(Bold Bardash) — The Years of Rice and Salt | The Years of Rice and Salt | Kim Stanley Robinson | Helper / jati guide |
| Bonhomius(the hermetic hermit, robot mendicant) — Altruizine or A True Account of How Bonhomius the Hermetic Hermit Tried to Bring About Universal Happiness | Altruizine or A True Account of How Bonhomius the Hermetic Hermit Tried to Bring About Universal Happiness | Stanislaw Lem | Protagonist and narrator |
| Boomer — Les Robinsonades | Les Robinsonades | Stanislaw Lem | Imaginary Scullery Boy |
| Boomzilla — All Tomorrow's Parties | All Tomorrow's Parties | William Gibson | Street child/opportunist |
| Boone Chu(Boone, Bunchoo) — Pattern Recognition | Pattern Recognition | William Gibson | Fellow investigator |
| Borazjani(H. X. Borazjani) — Green Mars | Green Mars | Kim Stanley Robinson | Minor/functional |
| Borges(J.L.B.) — The Form of the Sword | The Form of the Sword | Jorge Luis Borges | Military commander |
| Boris Nagorny(Nagorny) — Revelation Space | Revelation Space | Alastair Reynolds | Deceased Gunnery Officer |
| Boris Rodrigo(Rod, Lt Rodrigo, Boris) — Rendezvous with Rama | Rendezvous with Rama | Arthur C. Clarke | Communications officer / pilot |
| Borri — Ammonite | Ammonite | Nicola Griffith | Echraidhe healer |
| Bosquinha(Mayor, Mayor Bosquinha) — Speaker for the Dead | Speaker for the Dead | Orson Scott Card | Opponent/authority |
| Bothari(Sergeant Bothari, Sergeant) — Barrayar | Barrayar | Lois McMaster Bujold | actantial helper |
| Bovine — A Perfect Vacuum | A Perfect Vacuum | Stanislaw Lem | Creator of computer simulation |
| Boy AF Rex(Rex) — Klara and the Sun | Klara and the Sun | Kazuo Ishiguro | Artificial Friend |
| Bradley — Stranger in a Strange Land | Stranger in a Strange Land | Robert A. Heinlein | Government liaison |
| Brahma(Madeleine, the god, Lord Brahma +8) — Lord of Light | Lord of Light | Roger Zelazny | antagonist/ambiguous authority |
| Brann — The Foundation Trilogy | The Foundation Trilogy | Isaac Asimov | Dahlite guard / Calvinian community member |
| Brawne Lamia — Hyperion | Hyperion | Dan Simmons | Detective/pilgrim narrator |
| Brawne Lamia(Lamia, Brawne) — The Fall of Hyperion | The Fall of Hyperion | Dan Simmons | Pilgrim; former private investigator |
| Breach interlocutor(older man, the man) — The City & The City | The City & The City | China Miéville | Breach avatar and interrogator |
| Breq(One Esk Fourteen, Justice of Toren One Esk, One Esk +6) — Ancillary Justice | Ancillary Justice | Ann Leckie | narrator/protagonist |
| Breq(Fleet Captain Breq Mianaai, One Esk Nineteen, Fleet Captain +3) — Ancillary Sword | Ancillary Sword | Ann Leckie | Protagonist / Fleet Captain |
| Brian — Dreamsnake | Dreamsnake | Vonda N. McIntyre | minor |
| Brian — Nova | Nova | Samuel R. Delany | Racing yacht crew |
| Brian Abnett(Brian) — Redshirts | Redshirts | John Scalzi | 21st-century actor, doppelgänger of Dahl |
| Bridger — Seven Surrenders | Seven Surrenders | Ada Palmer | Miracle worker |
| Bridger — Too Like the Lightning | Too Like the Lightning | Ada Palmer | Hidden child with miraculous powers |
| Brody(Brigadier Judge Brody) — The Moon Is a Harsh Mistress | The Moon Is a Harsh Mistress | Robert A. Heinlein | actantial:helper |
| Brody DeLupa(Vice President, Proxy, Vice President DeLupa) — Seven Surrenders | Seven Surrenders | Ada Palmer | Humanist Vice President and Proxy of the Anonymous |
| Brody DeLupa(Vice President DeLupa) — Too Like the Lightning | Too Like the Lightning | Ada Palmer | Humanist Vice President / Proxy |
| Bronwen — Stand on Zanzibar | Stand on Zanzibar | John Brunner | Donald's contact/companion in Yatakang |
| Brood(link man) — Neuromancer | Neuromancer | William Gibson | Panther Modern link man |
| Brook — Fledgling | Fledgling | Octavia E. Butler | Shori's human symbiont |
| Brookida — Startide Rising | Startide Rising | David Brin | Elderly neo-dolphin scientist |
| Brother Armbruster — A Canticle for Leibowitz | A Canticle for Leibowitz | Walter M. Miller, Jr. | Opponent/Traditionalist |
| Brother Edward Behr(Teddy Behr, Brother Edward, Ed +2) — The Sparrow | The Sparrow | Mary Doria Russell | Sandoz's caretaker in Rome |
| Brother Felix(the Capellan, Felix) — Take Back Plenty | Take Back Plenty | Colin Greenland | antagonist |
| Brother Francis Gerard(Francis, the novice, Brother Francis) — A Canticle for Leibowitz | A Canticle for Leibowitz | Walter M. Miller, Jr. | Protagonist/Subject |
| Brother Jeris — A Canticle for Leibowitz | A Canticle for Leibowitz | Walter M. Miller, Jr. | Minor antagonist |
| Brother Joshua(the last monk) — A Canticle for Leibowitz | A Canticle for Leibowitz | Walter M. Miller, Jr. | actantial:subject |
| Brother Kornhoer(the inventor, the monastic inventor) — A Canticle for Leibowitz | A Canticle for Leibowitz | Walter M. Miller, Jr. | Helper/Innovator |
| Brother of Twelve Shadows(Senior Brother) — Startide Rising | Startide Rising | David Brin | Antagonist / Brothers of the Night operative |
| Brother Slippers(Slippers) — Echopraxia | Echopraxia | Peter Watts | Monk |
| Brotherman — Spook Country | Spook Country | William Gibson | Operative |
| Brothers of the Night — Startide Rising | Startide Rising | David Brin | Galactic patron race, antagonist fleet |
| Brown(the man from Union Square) — Spook Country | Spook Country | William Gibson | Captor and investigator |
| Brownie(Robin Goodfellow, Robin) — Queen of the States | Queen of the States | Lisa Goldstein | Helper / familiar |
| Bruce — The Coral Bones | The Coral Bones | Jynne Martin | Witness/tourist |
| Bruxinha — Speaker for the Dead | Speaker for the Dead | Orson Scott Card | minor character |
| Bryar Kosala(Kosala, Chair Kosala, Chair) — Seven Surrenders | Seven Surrenders | Ada Palmer | Chairwoman of the Cousins Hive |
| Bryar Kosala(Chair Kosala, Aunt Kosala, Kosala) — The Will to Battle | The Will to Battle | Ada Palmer | Leader of the Cousins Hive |
| Bryar Kosala(Chair Kosala, Mom, Bryar +2) — Too Like the Lightning | Too Like the Lightning | Ada Palmer | Cousin Chair and Servicer Program Director |
| Bubbles — The Calculating Stars | The Calculating Stars | Mary Robinette Kowal | other |
| Budur — The Years of Rice and Salt | The Years of Rice and Salt | Kim Stanley Robinson | protagonist/scientist |
| Buell Creedmore(Creedmore) — All Tomorrow's Parties | All Tomorrow's Parties | William Gibson | Country singer/Passenger |
| Bugsy(bugs@nouvelles, bugsy@nouvelles) — Air | Air | Geoff Ryman | Outside journalist contact |
| Buidze(Mr. Buidze) — The City & The City | The City & The City | China Miéville | Dig supervisor or manager |
| Bumble — A Closed and Common Orbit | A Closed and Common Orbit | Becky Chambers | helper |
| Bunny — Pattern Recognition | Pattern Recognition | William Gibson | Self-defense instructor |
| Bunny — Virtual Light | Virtual Light | William Gibson | Dispatcher |
| Bunub — The Dispossessed | The Dispossessed | Ursula K. Le Guin | Anarresti acquaintance |
| Buoult — Startide Rising | Startide Rising | David Brin | Thennanin general-protector |
| Buoult — The Uplift War | The Uplift War | David Brin | Thennanin undercommander |
| Burghart — Stories of Your Life and Others | Stories of Your Life and Others | Ted Chiang | Linguist/Translator |
| Burghart — Story of Your Life | Story of Your Life | Ted Chiang | Linguist |
| Busho — The Years of Rice and Salt | The Years of Rice and Salt | Kim Stanley Robinson | helper |
| Buster Friendly — Do Androids Dream of Electric Sheep? | Do Androids Dream of Electric Sheep? | Philip K. Dick | supporting |
| Butterfly(Tianfei) — The Years of Rice and Salt | The Years of Rice and Salt | Kim Stanley Robinson | Indigenous child, talisman |
| Buzz — Lost Futures | Lost Futures | Lisa Tuttle | Institutional therapist/teacher |
| Buzz-cut boy(man from the bar, assassin) — All Tomorrow's Parties | All Tomorrow's Parties | William Gibson | Assassin |
| Byr Genar-Hofoen(Genar-Hofoen, human, Byr) — Excession | Excession | Iain M. Banks | Special Circumstances agent |
| C — The Lottery in Babylon | The Lottery in Babylon | Jorge Luis Borges | Hypothetical individual |
| Cadaverius Malignus — Altruizine or A True Account of How Bonhomius the Hermetic Hermit Tried to Bring About Universal Happiness | Altruizine or A True Account of How Bonhomius the Hermetic Hermit Tried to Bring About Universal Happiness | Stanislaw Lem | Ancient scholar |
| Caitlin — Agency | Agency | William Gibson | Stets's associate |
| Callahan — Division by Zero | Division by Zero | Ted Chiang | Mathematician at Berkeley |
| Callahan — Stories of Your Life and Others | Stories of Your Life and Others | Ted Chiang | Colleague |
| Camberley — Blackout/All Clear | Blackout/All Clear | Connie Willis | FANY unit member |
| Cameron — Forever Peace | Forever Peace | Joe Haldeman | helper |
| Cameron Paj — Ancillary Sword | Ancillary Sword | Ann Leckie | crew member |
| Candi — Forever Peace | Forever Peace | Joe Haldeman | Soldierboy mechanic, platoon member |
| Capt. Richard Madden(Madden) — The Circular Ruins | The Circular Ruins | Jorge Luis Borges | Arresting officer / Irishman |
| Capt. Richard Madden — The Form of the Sword | The Form of the Sword | Jorge Luis Borges | English agent, pursuer |
| Capt. Richard Madden — The Garden of Forking Paths | The Garden of Forking Paths | Jorge Luis Borges | Antagonist |
| Captain (Second Expedition)(Jonathan Williams) — The Martian Chronicles | The Martian Chronicles | Ray Bradbury | Earth expedition captain |
| Captain Abernathy(Lucius) — Redshirts | Redshirts | John Scalzi | Commanding officer / Narrative anchor |
| Captain Blackstone(Blackie, Cap'n Blackie) — Starship Troopers | Starship Troopers | Robert A. Heinlein | sender/superior officer |
| Captain Cameron — A Desolation Called Peace | A Desolation Called Peace | Arkady Martine | fictional hero |
| Captain Darren — Ancillary Sword | Ancillary Sword | Ann Leckie | secondary character |
| Captain Deladrier(Yvette Deladrier, Hot Pilot) — Starship Troopers | Starship Troopers | Robert A. Heinlein | Ship captain / Rodger Young commander |
| Captain Devereux — Take Back Plenty | Take Back Plenty | Colin Greenland | secondary |
| Captain Frank — Take Back Plenty | Take Back Plenty | Colin Greenland | secondary |
| Captain Frankel(Blackie) — Starship Troopers | Starship Troopers | Robert A. Heinlein | Base commander / senior officer at Camp Currie |
| Captain Heinrich(Heinrich) — Stranger in a Strange Land | Stranger in a Strange Land | Robert A. Heinlein | Police antagonist |
| Captain Hetnys(Citizen Hetnys) — Ancillary Sword | Ancillary Sword | Ann Leckie | Captain of Sword of Atagaris / conspirator |
| Captain John Black — The Martian Chronicles | The Martian Chronicles | Ray Bradbury | Commander, Third Expedition |
| Captain Lord Padma Xav Vorpatril(Vorpatril, Lord Vorpatril, Lady Vorpatril) — Barrayar | Barrayar | Lois McMaster Bujold | supporting |
| Captain Miśnia — De Impossibilitate Vitae / De Impossibilitate Prognoscendi | De Impossibilitate Vitae / De Impossibilitate Prognoscendi | Stanislaw Lem | The nurse's second suitor |
| Captain Negri — Barrayar | Barrayar | Lois McMaster Bujold | supporting |
| Captain of the Mindful — The Dispossessed | The Dispossessed | Ursula K. Le Guin | Freighter Captain |
| Captain of the palace guard — Gruppenfuhrer Louis XVI | Gruppenfuhrer Louis XVI | Stanislaw Lem | Conspirator |
| Captain Siri — The Forever War | The Forever War | Joe Haldeman | Earth briefing officer |
| Captain Tolk — The Foundation Trilogy | The Foundation Trilogy | Isaac Asimov | minor |
| Captain Vaagen(Dr. Vaagen) — Barrayar | Barrayar | Lois McMaster Bujold | actantial helper |
| Captain Vel Osck(Captain Vel, Rose-and-Azure's host) — Ancillary Justice | Ancillary Justice | Ann Leckie | opponent |
| Captain Wilder — The Martian Chronicles | The Martian Chronicles | Ray Bradbury | Commander, Fourth Expedition |
| Cardinal du Sauterne — Gruppenfuhrer Louis XVI | Gruppenfuhrer Louis XVI | Stanislaw Lem | Court Cardinal |
| Cardoso — The Form of the Sword | The Form of the Sword | Jorge Luis Borges | Former landowner |
| Caria(the Widow Caria, widow of Palma) — Paladin of Souls | Paladin of Souls | Lois McMaster Bujold | other |
| Carl(Mr. Norwood) — Division by Zero | Division by Zero | Ted Chiang | Experimental biologist and Renee's husband |
| Carl — Starship Troopers | Starship Troopers | Robert A. Heinlein | Rico's civilian friend |
| Carl — Stories of Your Life and Others | Stories of Your Life and Others | Ted Chiang | Biologist, Renee's husband |
| Carl Hollywood — The Diamond Age | The Diamond Age | Neal Stephenson | Actor/director/technologist |
| Carlito(Uncle) — Spook Country | Spook Country | William Gibson | Family authority figure |
| Carlos — Take Back Plenty | Take Back Plenty | Colin Greenland | minor/contact |
| Carlos — The Peripheral | The Peripheral | William Gibson | Volunteer EMT, security |
| Carlos Argentino Daneri(Carlos) — The Form of the Sword | The Form of the Sword | Jorge Luis Borges | Poet/Cousin |
| Carlos Argentino Daneri(Carlos Argentino) — Tlön, Uqbar, Orbis Tertius | Tlön, Uqbar, Orbis Tertius | Jorge Luis Borges | Host |
| Carlos Mastronardi — Ficciones (Tlön, Uqbar, Orbis Tertius) | Ficciones (Tlön, Uqbar, Orbis Tertius) | Jorge Luis Borges | Narrator's friend |
| Carlos Rivera(Dangerous Knowledge, Greatest Lesser Scooch-a-mout) — Rainbows End | Rainbows End | Vernor Vinge | supporting |
| Carlyle — The Windup Girl | The Windup Girl | Paolo Bacigalupi | Trade broker and coup architect |
| Carlyle Foster(Carlyle, Foster, Cousin Foster) — Seven Surrenders | Seven Surrenders | Ada Palmer | Sensayer and Gag-gene, nephew to Ganymede |
| Carlyle Foster(Carlyle, sensayer, Cousin Foster +5) — Too Like the Lightning | Too Like the Lightning | Ada Palmer | Sensayer and Gag-gene |
| Carlyle Foster-Kraye(ex-Cousin, Carlyle, Special Informant) — Perhaps the Stars | Perhaps the Stars | Ada Palmer | Mycroft's companion and tactical ally |
| Carmen(Carmencita, Carmencita Ibañez) — Starship Troopers | Starship Troopers | Robert A. Heinlein | minor character/romantic interest |
| Carmouche(Reynard Carmouche, Dr. Carmouche) — The Calculating Stars | The Calculating Stars | Mary Robinette Kowal | supporting |
| Carnelian — The Fifth Season | The Fifth Season | N.K. Jemisin | Instructor |
| Carolus Hourcade — Pierre Menard, Author of the Quixote | Pierre Menard, Author of the Quixote | Jorge Luis Borges | helper |
| Carruthers(Commander Carruthers) — To Say Nothing of the Dog | To Say Nothing of the Dog | Connie Willis | Fellow time-traveller |
| Carson(Movie-looking white man) — All Tomorrow's Parties | All Tomorrow's Parties | William Gibson | Chevette's abusive ex-boyfriend |
| Case(cowboy, Cutter, old son) — Neuromancer | Neuromancer | William Gibson | Console cowboy and protagonist |
| Casimir Perry(Prime Minister) — Seven Surrenders | Seven Surrenders | Ada Palmer | Europe's Second-Choice Prime Minister |
| Casimir Perry(Merion Kraye, Gunman) — The Will to Battle | The Will to Battle | Ada Palmer | Assassin and antagonist |
| Cassaway — Redshirts | Redshirts | John Scalzi | Expendable crewman |
| Cassil — Ammonite | Ammonite | Nicola Griffith | Helper / first indigenous contact |
| Catherine Lao — Cyteen | Cyteen | C. J. Cherryh | Councillor; Bureau of Information |
| Cathy Minami — Stories of Your Life and Others | Stories of Your Life and Others | Ted Chiang | 3rd-year student |
| Cathy Wickham — Timescape | Timescape | Gregory Benford | helper |
| Catlin(AC-7892, Catlin II) — Cyteen | Cyteen | C. J. Cherryh | azi companion/POV character |
| Cato — Seven Surrenders | Seven Surrenders | Ada Palmer | Scientist / Member of Saneer-Weeksbooth |
| Cato Weeksbooth(Cato-Helen, Cato, Helen +1) — Perhaps the Stars | Perhaps the Stars | Ada Palmer | Prisoner and H.E.L.E.N. subject |
| Cato Weeksbooth — The Will to Battle | The Will to Battle | Ada Palmer | Target and defector to Utopia |
| Cato Weeksbooth(Cato, Dr. Weeksbooth) — Too Like the Lightning | Too Like the Lightning | Ada Palmer | Scientist and Museum Volunteer |
| Cattilara(Catti, Lady Cattilara, Marchess of Porifors +3) — Paladin of Souls | Paladin of Souls | Lois McMaster Bujold | opponent/victim |
| Cavalieri — The Library of Babel | The Library of Babel | Jorge Luis Borges | Mathematician |
| Cayce Pollard(Cayce, CayceP, Casey) — Pattern Recognition | Pattern Recognition | William Gibson | Protagonist and coolhunter |
| Celene(Cele) — Dawn | Dawn | Octavia E. Butler | Human survivor |
| Celene — Imago | Imago | Octavia E. Butler | Human survivor |
| Celia — Fledgling | Fledgling | Octavia E. Butler | Shori's human symbiont |
| Celu MacDonald — Echopraxia | Echopraxia | Peter Watts | Freelance Coder |
| Censor Jung(Censor) — Perhaps the Stars | Perhaps the Stars | Ada Palmer | War room participant |
| Central(Pre-CR Central, UnidentifiedSender) — Network Effect | Network Effect | Martha Wells | other |
| Cerebron of Umptor — The Third Sally or The Dragons of Probability | The Third Sally or The Dragons of Probability | Stanislaw Lem | Great teacher |
| Cezar Kouska(Benedykt Kouska, Professor B. Kouska) — A Perfect Vacuum | A Perfect Vacuum | Stanislaw Lem | Fictional Author / Professor |
| Chad Mulligan — American Gods | American Gods | Neil Gaiman | minor human authority |
| Chad Mulligan(Chad C. Mulligan) — Stand on Zanzibar | Stand on Zanzibar | John Brunner | Helper / Ideological Counterpoint |
| Chagatai — Perhaps the Stars | Perhaps the Stars | Ada Palmer | Blacklaw Guard |
| Chagatai — The Will to Battle | The Will to Battle | Ada Palmer | Town Hall speaker |
| Chamrajnagar — Ender's Game | Ender's Game | Orson Scott Card | IFCom Admiral / institutional counterweight |
| Chang(Rupert Chang, driver-pilot Chang) — The Fountains of Paradise | The Fountains of Paradise | Arthur C. Clarke | helper |
| Chani(hija de Liet, Sihaya) — Dune | Dune | Frank Herbert | companion/partner |
| Charitable View — Excession | Excession | Iain M. Banks | Cliff class superlifter |
| Charles — Blackout/All Clear | Blackout/All Clear | Connie Willis | Fellow historian |
| Charles Paulson(you, Crewman Hester) — Redshirts | Redshirts | John Scalzi | Showrunner/executive producer of Chronicles of the Intrepid |
| Charles Yan Sen(Dr. Sen) — Childhood's End | Childhood's End | Arthur C. Clarke | Colony administrator |
| Charlie — Acceptance | Acceptance | Jeff VanderMeer | Saul's romantic partner |
| Charlie(Charlie Moore, Captain Moore) — The Forever War | The Forever War | Joe Haldeman | Close companion and staff officer |
| Charlie Dart(Charlie, Charles Dart) — Startide Rising | Startide Rising | David Brin | Neo-chimpanzee geologist/planetologist |
| Charlotte — Blue Mars | Blue Mars | Kim Stanley Robinson | actantial:helper |
| Charlotte — Red Mars | Red Mars | Kim Stanley Robinson | Constitutional scholar, congress framework builder |
| Charlotte Armstrong(Charlotte) — New York 2140 | New York 2140 | Kim Stanley Robinson | Met Life tower board member |
| Chase — The Lifecycle of Software Objects | The Lifecycle of Software Objects | Ted Chiang | Binary Desire representative |
| Chaya — The Windup Girl | The Windup Girl | Paolo Bacigalupi | Jaidee's wife / absent figure |
| Chaypas VaKashan(Chaypas) — The Sparrow | The Sparrow | Mary Doria Russell | Runa woman, village host |
| Che-ong(Che) — Nova | Nova | Samuel R. Delany | Party guest |
| Chelsea(Madam Fix-It) — Blindsight | Blindsight | Peter Watts | Neuro-technician / Ex-girlfriend |
| Chen — Redshirts | Redshirts | John Scalzi | Minor crewman |
| Chenewich(Sardon rem ir Chenewich) — The Left Hand of Darkness | The Left Hand of Darkness | Ursula K. Le Guin | helper |
| Cheney — Acceptance | Acceptance | Jeff VanderMeer | Science Division member |
| Cheney — Authority | Authority | Jeff VanderMeer | Southern Reach Staff Member |
| Cheradenine Zakalwe(Zakalwe, General, Mr. Staberinde +11) — Use of Weapons | Use of Weapons | Iain M. Banks | Zakalwe's Sister / Estranged Relative |
| Cheroke — The Martian Chronicles | The Martian Chronicles | Ray Bradbury | Crewman, Fourth Expedition |
| Cherry Chesterfield(Cherry) — Mona Lisa Overdrive | Mona Lisa Overdrive | William Gibson | Medical technician |
| Chevalier — Too Like the Lightning | Too Like the Lightning | Ada Palmer | Club patron |
| Chevette(Chevette Washington, Biker-looking bitch, Skinner's girl) — All Tomorrow's Parties | All Tomorrow's Parties | William Gibson | Former bicycle messenger |
| Chevette-Marie Washington(Chevette, Vette, the girl +3) — Virtual Light | Virtual Light | William Gibson | Bike messenger and bridge resident |
| Chia — Idoru | Idoru | William Gibson | Fourteen-year-old Lo/Rez fan |
| Chifoilisk — The Dispossessed | The Dispossessed | Ursula K. Le Guin | Urrasti/Thuvian physicist and agent |
| Child — The First Sally or The Trap of Gargantius | The First Sally or The Trap of Gargantius | Stanislaw Lem | Undercover agent/bait |
| Chinedum Ofoegbu — Echopraxia | Echopraxia | Peter Watts | Bicameral node |
| Ching Hso-lin(Ching) — I, Robot | I, Robot | Isaac Asimov | Eastern Region Vice-Co-ordinator |
| Chlorian Theoreticus(Chlorian Theoreticus the Proph) — Tale of the Three Storytelling Machines of King Genius | Tale of the Three Storytelling Machines of King Genius | Stanislaw Lem | Bitter Philosopher |
| Chlorian Theoreticus the Proph(Greatest of Robots) — Altruizine or A True Account of How Bonhomius the Hermetic Hermit Tried to Bring About Universal Happiness | Altruizine or A True Account of How Bonhomius the Hermetic Hermit Tried to Bring About Universal Happiness | Stanislaw Lem | Deceased scholar |
| Chlorian Theoreticus the Proph(Theoreticus) — The Cyberiad | The Cyberiad | Stanislaw Lem | Pundit and Ontologist |
| Chmeee(Speaker, Speaker-To-Animals) — Ringworld | Ringworld | Larry Niven | actantial:object |
| Chooka Frood — The Demolished Man | The Demolished Man | Alfred Bester | Underworld figure |
| Chori — Use of Weapons | Use of Weapons | Iain M. Banks | Alien operative |
| Chorry(Chorry-Chorrykins) — Authority | Authority | Jeff VanderMeer | Control's Pet |
| Chrissie — Never Let Me Go | Never Let Me Go | Kazuo Ishiguro | Veteran student at the Cottages |
| Christopher Marlowe(Kit) — Queen of the States | Queen of the States | Lisa Goldstein | Protagonist (spy plot) |
| Churt Lyne — Excession | Excession | Iain M. Banks | Drone |
| Cinzia — The Ministry for the Future | The Ministry for the Future | Kim Stanley Robinson | Wealthy elite |
| Claire — Ammonite | Ammonite | Nicola Griffith | Background / Danner's sister |
| Claire — Blue Mars | Blue Mars | Kim Stanley Robinson | Colleague |
| Claire — Green Mars | Green Mars | Kim Stanley Robinson | Biotique scientist |
| Claire — Red Mars | Red Mars | Kim Stanley Robinson | colleague / Biotique scientist |
| Clan Leader(Arevin's cousin) — Dreamsnake | Dreamsnake | Vonda N. McIntyre | helper / sender |
| Clara Glencairn(Clara) — The Form of the Sword | The Form of the Sword | Jorge Luis Borges | Philanthropist / Patrician |
| Claude — Forever Peace | Forever Peace | Joe Haldeman | Humanized soldierboy (named unit) |
| Claudia Zinnes(Claudia) — Timescape | Timescape | Gregory Benford | Collaborating physicist at Columbia |
| Clavally — The Snow Queen | The Snow Queen | Joan D. Vinge | Mentor / sibyl teacher |
| Clayton(Comrade Clayton) — The Moon Is a Harsh Mistress | The Moon Is a Harsh Mistress | Robert A. Heinlein | Hong Kong Party contact |
| Clearwater — Stars in My Pocket Like Grains of Sand | Stars in My Pocket Like Grains of Sand | Samuel R. Delany | Friend |
| Cleopatra(plastic Cleopatra) — Sexplosion | Sexplosion | Stanislaw Lem | Manikin |
| Cliff — Timescape | Timescape | Gregory Benford | minor character |
| Cloned assassin(ninja, visitor) — Neuromancer | Neuromancer | William Gibson | Enforcer for Tessier-Ashpool |
| Clovis Fearing(Fearing) — Agency | Agency | William Gibson | Investigator/Associate |
| Clym(Skina Clym, Skon Clym) — Stars in My Pocket Like Grains of Sand | Stars in My Pocket Like Grains of Sand | Samuel R. Delany | Acquaintance/Antagonist |
| Codes — Virtual Light | Virtual Light | William Gibson | Lowell's associate |
| Colin — Doomsday Book | Doomsday Book | Connie Willis | Mary's great-nephew, teenage companion |
| Colin(the ghost) — Mona Lisa Overdrive | Mona Lisa Overdrive | William Gibson | AI construct / Guide |
| Colin Anderson(Col) — The Separation | The Separation | Christopher Priest | Wireless operator |
| Colin Laney(Cohn Laney, Laney) — Idoru | Idoru | William Gibson | Quantitative data analyst |
| Colin Templer — Blackout/All Clear | Blackout/All Clear | Connie Willis | Oxford student / helper |
| Colleague — Exhalation | Exhalation | Ted Chiang | Safety monitor |
| Collins — Redshirts | Redshirts | John Scalzi | Department head / Opponent |
| Collins — The Forever War | The Forever War | Joe Haldeman | soldier |
| Colonel Bashar(the Sardaukar, coronel Bashar) — Dune | Dune | Frank Herbert | imperial agent |
| Colonel Fedmahn Kassad(Kassad, Captain Kassad, Colonel Kassad +1) — Hyperion | Hyperion | Dan Simmons | Soldier/pilgrim protagonist of embedded tale |
| Colonel Jack Kynock — The Forever War | The Forever War | Joe Haldeman | veteran officer / historical informant |
| Colonel Kassad(Fedmahn Kassad) — The Fall of Hyperion | The Fall of Hyperion | Dan Simmons | Pilgrim; FORCE military officer |
| Colonel Millchamp — The Uplift War | The Uplift War | David Brin | Military officer, council member |
| Colonel Napier — The Diamond Age | The Diamond Age | Neal Stephenson | Victorian military officer |
| Colonel Nielssen — Starship Troopers | Starship Troopers | Robert A. Heinlein | minor |
| Colonel Spence — The Diamond Age | The Diamond Age | Neal Stephenson | helper |
| Colonel Weber — Stories of Your Life and Others | Stories of Your Life and Others | Ted Chiang | Military commander |
| Colonel Weber — Story of Your Life | Story of Your Life | Ted Chiang | Military Commander |
| Commandant — Starship Troopers | Starship Troopers | Robert A. Heinlein | supporting |
| Commander Harold(Commander, the Commander) — Blackout/All Clear | Blackout/All Clear | Connie Willis | Elderly volunteer sailor |
| Commander Hoae — A Closed and Common Orbit | A Closed and Common Orbit | Becky Chambers | authority figure |
| Commander Kindrummer VI — Excession | Excession | Iain M. Banks | Affronter Navy Commander |
| Commander Kylie — The Uplift War | The Uplift War | David Brin | Military officer, council member |
| Commander Norton(Norton, Skipper, Bill +2) — Rendezvous with Rama | Rendezvous with Rama | Arthur C. Clarke | Protagonist / mission commander |
| Commander Q'eeng(Science Officer Q'eeng) — Redshirts | Redshirts | John Scalzi | Senior officer / Narrative instrument |
| Commander Risingmoon Parchseason IV(Commander) — Excession | Excession | Iain M. Banks | Affronter Commander |
| Commander Tiaund(Esk Decade Commander Tiaund) — Ancillary Justice | Ancillary Justice | Ann Leckie | Ship officer |
| Commissioner Crabbe(Crabbe) — The Demolished Man | The Demolished Man | Alfred Bester | bureaucratic authority |
| Commissioner Treviranus(Treviranus) — The Form of the Sword | The Form of the Sword | Jorge Luis Borges | Police Commissioner |
| Conner Penske(Conner) — Agency | Agency | William Gibson | Drone pilot and former Marine |
| Conner Penske(Conner, Mr. Penske) — The Peripheral | The Peripheral | William Gibson | Disabled veteran / Friend |
| Connie Perritt(Connie) — Stories of Your Life and Others | Stories of Your Life and Others | Ted Chiang | Acquaintance of Greco |
| Connie Perritt — Understand | Understand | Ted Chiang | Leon's former girlfriend |
| Conrad Loehr(Curt) — Dawn | Dawn | Octavia E. Butler | Violent human survivor |
| Conroy(Connie) — Count Zero | Count Zero | William Gibson | Logistics operative / Fixer |
| Constable Moore(Colonel Arthur Hornsby Moore) — The Diamond Age | The Diamond Age | Neal Stephenson | Mentor/benefactor |
| Construct Council(the avatar, the dead man, Avatar +1) — Perdido Street Station | Perdido Street Station | China Miéville | Artificial intelligence / Construct deity |
| Continuity(the house) — Mona Lisa Overdrive | Mona Lisa Overdrive | William Gibson | AI expert system |
| Control(John Rodriguez, John) — Acceptance | Acceptance | Jeff VanderMeer | Former Director of the Southern Reach / Survivor in Area X |
| Control(John, John Rodriguez, Director) — Authority | Authority | Jeff VanderMeer | Director of the Southern Reach / Protagonist |
| Cooper — Timescape | Timescape | Gregory Benford | Gordon's graduate student |
| Cora — The Handmaid's Tale | The Handmaid's Tale | Margaret Atwood | Martha in the Commander's household |
| Corain(Councillor Corain, Mikhail Corain, ser Corain) — Cyteen | Cyteen | C. J. Cherryh | Head of Centrist minority in the Council of Nine; political antagonist to Emory |
| Cordelia Naismith Vorkosigan(milady, Captain Naismith, regent-consort +15) — Barrayar | Barrayar | Lois McMaster Bujold | actantial opponent/helper |
| Cordwainer Appelbe — The Uplift War | The Uplift War | David Brin | nominal human official |
| Coredwell Minmun(Spokesman Coredwell Minmun) — The Fall of Hyperion | The Fall of Hyperion | Dan Simmons | Ouster Tribunal member |
| Cornel MASON(Martin, Mycroft MASON II, Junior Emperor +9) — Perhaps the Stars | Perhaps the Stars | Ada Palmer | Supreme defender of the Masonic IMPERIUM |
| Cornel MASON(Donatien, Jehovah, Child +22) — Seven Surrenders | Seven Surrenders | Ada Palmer | The Imperator Destinatus / Heir to multiple Hives |
| Cornel MASON(Stranger, Visitor, Tai-kun +10) — Too Like the Lightning | Too Like the Lightning | Ada Palmer | Hiveless Tribune and unofficial Tenth Mitsubishi Director |
| Cornfed Daihat(Cornfed) — Perdido Street Station | Perdido Street Station | China Miéville | Artist and friend of Lin |
| Corporal Bevins — Blackout/All Clear | Blackout/All Clear | Connie Willis | Minor / hospital patient |
| Cortez — The Forever War | The Forever War | Joe Haldeman | senior NCO / later commander |
| Corundum(Coru) — The Fifth Season | The Fifth Season | N.K. Jemisin | Son of Syenite and Alabaster |
| Corwi(Constable Corwi, Lizbyet, Grade-one constable +1) — The City & The City | The City & The City | China Miéville | Constable in the Besźel police force |
| Cosima(Cozzy) — Lost Futures | Lost Futures | Lisa Tuttle | minor |
| Councillor Chavez — Cyteen | Cyteen | C. J. Cherryh | other |
| Councilor Albedo — The Fall of Hyperion | The Fall of Hyperion | Dan Simmons | TechnoCore representative / AI projection |
| Councilor Nansen — The Fall of Hyperion | The Fall of Hyperion | Dan Simmons | TechnoCore AI representative |
| Counsellor Lukin — A Closed and Common Orbit | A Closed and Common Orbit | Becky Chambers | bureaucratic opponent |
| Count de Vecchio — To Say Nothing of the Dog | To Say Nothing of the Dog | Connie Willis | Madame Iritosky's accomplice |
| Count Fenring(MF, Dama Fenring, el Conde) — Dune | Dune | Frank Herbert | actantial:helper |
| Country house owner(The owner) — The Circular Ruins | The Circular Ruins | Jorge Luis Borges | Hotel proprietor |
| Coyote(the coyote, Desmond) — Blue Mars | Blue Mars | Kim Stanley Robinson | Trickster / underground network operator |
| Coyote(Desmond) — Green Mars | Green Mars | Kim Stanley Robinson | Trickster/smuggler; underground network operator |
| Coyote — Red Mars | Red Mars | Kim Stanley Robinson | Trickster guide / underground operative |
| Crab creature(the crab, the beetle) — Rendezvous with Rama | Rendezvous with Rama | Arthur C. Clarke | Raman entity |
| Crack — The Fifth Season | The Fifth Season | N.K. Jemisin | Grit |
| Craig Schrope(Schrope, Craig) — Pushing Ice | Pushing Ice | Alastair Reynolds | Subordinate and UEE Liaison |
| Creideiki — Startide Rising | Startide Rising | David Brin | Incapacitated captain aboard the skiff |
| Cress — The Snow Queen | The Snow Queen | Joan D. Vinge | Helper / crew member |
| Cristian Nilsen(Cristian Nelson, Cristian, Eduardo Nelson +1) — Tlön, Uqbar, Orbis Tertius | Tlön, Uqbar, Orbis Tertius | Jorge Luis Borges | Younger brother |
| Crone / shaman — The Snow Queen | The Snow Queen | Joan D. Vinge | Nomad shaman |
| Crucifax — The Cyberiad | The Cyberiad | Stanislaw Lem | Citizen |
| Cullcullabra — Startide Rising | Startide Rising | David Brin | Pil Librarian aboard Krat's vessel |
| Cullis(the older man, the old man) — Use of Weapons | Use of Weapons | Iain M. Banks | Zakalwe's companion |
| Culture ship(Attitude Adjuster, traitor ship) — Excession | Excession | Iain M. Banks | Traitorous Culture Ship |
| Cunha — Starship Troopers | Starship Troopers | Robert A. Heinlein | minor |
| Curate(Bug-Eyes, Mr. C (candidate)) — To Say Nothing of the Dog | To Say Nothing of the Dog | Connie Willis | Curate at St. Michael's Coventry |
| Curator Joje — A Closed and Common Orbit | A Closed and Common Orbit | Becky Chambers | gatekeeper |
| Curt — Imago | Imago | Octavia E. Butler | Human survivor |
| Cutie(QT-1, the Prophet) — I, Robot | I, Robot | Isaac Asimov | actantial:opponent |
| Cyana Morgan(Cyana, Aunt Cyana) — Nova | Nova | Samuel R. Delany | Museum Curator |
| Cybercount Cyberhazy(the princess' Elector) — The Cyberiad | The Cyberiad | Stanislaw Lem | Suitor / Antagonist |
| Cynthia — Pattern Recognition | Pattern Recognition | William Gibson | Cayce's mother |
| Cynthia E.(Cynthia) — Never Let Me Go | Never Let Me Go | Kazuo Ishiguro | Hailsham student |
| Cyril — To Say Nothing of the Dog | To Say Nothing of the Dog | Connie Willis | Comic animal companion |
| Czernobog — American Gods | American Gods | Neil Gaiman | Reluctant ally / antagonist-helper |
| Czigo — Dune | Dune | Frank Herbert | opponent |
| D.W. Yarbrough(Dalton Wesley Yarbrough, Father Yarbrough, D.W. +2) — The Sparrow | The Sparrow | Mary Doria Russell | New Orleans Jesuit Provincial; future mission commander |
| Da5id(Da5id Meier) — Snow Crash | Snow Crash | Neal Stephenson | secondary |
| Dad(William Thomas) — The Martian Chronicles | The Martian Chronicles | Ray Bradbury | Father / former state governor |
| Daedra — The Peripheral | The Peripheral | William Gibson | Artist and Wilf's ex |
| Daft Naimy(the Summer Prophet) — The Snow Queen | The Snow Queen | Joan D. Vinge | minor/symbolic |
| Dajeil(Dajeil Gelian) — Excession | Excession | Iain M. Banks | Isolated passenger |
| Dajeil lookalike — Excession | Excession | Iain M. Banks | Mysterious woman |
| Dalissa — Lord of Light | Lord of Light | Roger Zelazny | helper |
| Damaya's Mother(Mother) — The Fifth Season | The Fifth Season | N.K. Jemisin | Damaya's parent |
| Damek — Adulthood Rites | Adulthood Rites | Octavia E. Butler | Raider |
| Damek — Imago | Imago | Octavia E. Butler | Human raider |
| Damien — Pattern Recognition | Pattern Recognition | William Gibson | Cayce's friend and filmmaker |
| Damqiya — Stories of Your Life and Others | Stories of Your Life and Others | Ted Chiang | Miner |
| Damqiya — Tower of Babylon | Tower of Babylon | Ted Chiang | Elamite miner |
| Dan(Blind Dan) — Nova | Nova | Samuel R. Delany | Former cyborg stud |
| Dan Sylveste(Sylveste, Doctor) — Revelation Space | Revelation Space | Alastair Reynolds | Scientist, prisoner, and subject of a biography |
| Dana — Anxiety Is the Dizziness of Freedom | Anxiety Is the Dizziness of Freedom | Ted Chiang | Support Group Facilitator, Therapist |
| Dana — Exhalation | Exhalation | Ted Chiang | Therapist / Support Group Facilitator |
| Danaë(Mariscala Danaë, Mariscala) — Perhaps the Stars | Perhaps the Stars | Ada Palmer | Negotiator and leader |
| Danaquil Lu — The Snow Queen | The Snow Queen | Joan D. Vinge | Supporting / Clavally's partner |
| Dane Metchnikov(Dane) — Gateway | Gateway | Frederik Pohl | Proctor |
| Danel — The Stone Sky | The Stone Sky | N. K. Jemisin | Helper / Strongback general |
| Danica Elliott(Mrs. Elliott) — Virtual Light | Virtual Light | William Gibson | RV driver / Tourist |
| Daniel(my father) — Among Others | Among Others | Jo Walton | passive helper / manipulated figure |
| Daniel Brüks(Dan, roach, baseline +3) — Echopraxia | Echopraxia | Peter Watts | Protagonist and baseline human biologist |
| Daniel Gordon — Fledgling | Fledgling | Octavia E. Butler | Gordon family member |
| Daniel Simón Azevedo — Death and the Compass | Death and the Compass | Jorge Luis Borges | Victim / Criminal |
| Daniel Taglia — Liking What You See: A Documentary | Liking What You See: A Documentary | Ted Chiang | Professor of comparative literature at Pembleton |
| Daniel Taglia — Stories of Your Life and Others | Stories of Your Life and Others | Ted Chiang | Professor of comparative literature |
| Danny A. — Gateway | Gateway | Frederik Pohl | actantial:helper |
| Dao — Blue Mars | Blue Mars | Kim Stanley Robinson | secondary |
| Dao — Green Mars | Green Mars | Kim Stanley Robinson | rival |
| Dao — Red Mars | Red Mars | Kim Stanley Robinson | second-generation Martian |
| Daos Ceit(Inspector Adjunct Ceit) — Ancillary Justice | Ancillary Justice | Ann Leckie | actantial:helper |
| Daphne — Blackout/All Clear | Blackout/All Clear | Connie Willis | helper |
| Darckense(Darkle) — Use of Weapons | Use of Weapons | Iain M. Banks | Sister of Cheradenine |
| Darj Tarats(Councilor Tarats, Councilor for the Miners) — A Desolation Called Peace | A Desolation Called Peace | Arkady Martine | Councilor for the Miners, Lsel Station |
| Darryl(Musashi) — Pattern Recognition | Pattern Recognition | William Gibson | Collaborator/Translator |
| Daryl — Fledgling | Fledgling | Octavia E. Butler | Symbiont |
| Dave — Ancillary Sword | Ancillary Sword | Ann Leckie | secondary character / victim |
| Dave(DV-5) — I, Robot | I, Robot | Isaac Asimov | actantial:object |
| David Bowden(Bowden) — The City & The City | The City & The City | China Miéville | Murderer / Academic |
| David Grant — Forever Peace | Forever Peace | Joe Haldeman | supporting |
| David Jerusalem(Jerusalem) — Tlön, Uqbar, Orbis Tertius | Tlön, Uqbar, Orbis Tertius | Jorge Luis Borges | Poet/Victim |
| David Serachin(David) — Perdido Street Station | Perdido Street Station | China Miéville | Isaac's labmate / Informant |
| Davidson — Authority | Authority | Jeff VanderMeer | Scientist |
| Davies — Seventy-Two Letters | Seventy-Two Letters | Ted Chiang | Agent of Lord Fieldhurst |
| Davis(Ensign Davis) — Redshirts | Redshirts | John Scalzi | Minor crewman / Sacrificial extra |
| Dawn Ardent(Dawn, née Higgins) — Stranger in a Strange Land | Stranger in a Strange Land | Robert A. Heinlein | Fosterite convert/exotic dancer |
| Dearri(Dean) — The Dispossessed | The Dispossessed | Ursula K. Le Guin | Urrasti party guest |
| Defense Minister(Lord Ragelle) — A Canticle for Leibowitz | A Canticle for Leibowitz | Walter M. Miller, Jr. | actantial:opponent |
| Dehkiaht — Adulthood Rites | Adulthood Rites | Octavia E. Butler | Subadult ooloi |
| Dehkiaht — Imago | Imago | Octavia E. Butler | Subadult ooloi |
| Deirdre — Stand on Zanzibar | Stand on Zanzibar | John Brunner | supporting |
| Dekakel Onchu — A Desolation Called Peace | A Desolation Called Peace | Arkady Martine | Councilor for the Pilots, Lsel Station |
| Del — Hyperion | Hyperion | Dan Simmons | Bikura informant |
| Delahanty(Major Delahanty) — Stand on Zanzibar | Stand on Zanzibar | John Brunner | Engrelay Satelserv editor/handler |
| Delarmi(Speakeress Delarmi, Speaker Delarmi) — Foundation's Edge | Foundation's Edge | Isaac Asimov | Senior Speaker of the Second Foundation |
| Demaere Oiie(Oiie) — The Dispossessed | The Dispossessed | Ursula K. Le Guin | Urrasti physicist |
| Dembélé(Secretary-General of the United Nations, Standard-Bearer of the Great African Reservation, U.N. Secretary-General Dembélé) — Perhaps the Stars | Perhaps the Stars | Ada Palmer | U.N. Secretary-General |
| Demon of the Second Kind — The Cyberiad | The Cyberiad | Stanislaw Lem | Information Generator |
| Denison(Ben, Immie, Ben Denison +1) — The Gods Themselves | The Gods Themselves | Isaac Asimov | Earth physicist seeking rehabilitation on the Moon |
| Dennie Sudman(Dennie) — Startide Rising | Startide Rising | David Brin | Human exobiologist on the skiff |
| Denys Nye(Denys, Uncle Denys, DN) — Cyteen | Cyteen | C. J. Cherryh | Senior Reseune administrator, Ari II's guardian |
| Denz Ay — Ancillary Justice | Ancillary Justice | Ann Leckie | Local Orsian resident / helper |
| Derek Brooks(Derek) — Exhalation | Exhalation | Ted Chiang | Digient owner and former Blue Gamma employee |
| Derek Brooks(Derek) — The Lifecycle of Software Objects | The Lifecycle of Software Objects | Ted Chiang | Avatar designer and digient owner |
| Derick Wolski — Dawn | Dawn | Octavia E. Butler | Human survivor |
| Derkhan Blueday(Derkhan, Dee, Blueday) — Perdido Street Station | Perdido Street Station | China Miéville | Art critic for the Beacon |
| Derrick — Imago | Imago | Octavia E. Butler | Human survivor |
| Desar — The Dispossessed | The Dispossessed | Ursula K. Le Guin | Anarresti mathematician |
| Deshati — The Stone Sky | The Stone Sky | N. K. Jemisin | Found Moon orogene child |
| Desi O'Callaghan(Assistant Commissioner, Deputy O'Callaghan) — Perhaps the Stars | Perhaps the Stars | Ada Palmer | High-ranking police officer |
| Detective Inspector Lowbeer(Lowbeer, Inspector Lowbeer, Ainsley James Gryffyd Lowbeer Holdsworth +2) — The Peripheral | The Peripheral | William Gibson | Authority figure from the future |
| Dev — The Fountains of Paradise | The Fountains of Paradise | Arthur C. Clarke | minor |
| Devi(Deviana Morris) — Ancillary Justice | Ancillary Justice | Ann Leckie | protagonist (Fortune's Pawn teaser) |
| Dhu — Blue Mars | Blue Mars | Kim Stanley Robinson | Sufi community member |
| Dhu el-Nun — Blue Mars | Blue Mars | Kim Stanley Robinson | Sufi community leader |
| Dhu el-Nun — Green Mars | Green Mars | Kim Stanley Robinson | supporting |
| Dhu el-Nun — Red Mars | Red Mars | Kim Stanley Robinson | Sufi leader / local guide |
| Diamond — Lost Futures | Lost Futures | Lisa Tuttle | minor |
| Diana — Blue Mars | Blue Mars | Kim Stanley Robinson | Fourth-generation Martian |
| Diana — Green Mars | Green Mars | Kim Stanley Robinson | Native Martian / Deep Waters colleague |
| Diana — Red Mars | Red Mars | Kim Stanley Robinson | Fourth-generation Martian / Hellas specialist |
| Diana(Doc Alsever, Diana Alsever-Moore) — The Forever War | The Forever War | Joe Haldeman | Medical officer |
| Diana Philomel(Lady Diana) — The Fall of Hyperion | The Fall of Hyperion | Dan Simmons | Royalist conspirator; interrogates Severn under truthtalk |
| Dichaan('Chaan) — Adulthood Rites | Adulthood Rites | Octavia E. Butler | Akin's Oankali father |
| Dichaan — Dawn | Dawn | Octavia E. Butler | Oankali male |
| Dichaan — Imago | Imago | Octavia E. Butler | Oankali male parent |
| Different Tan — Excession | Excession | Iain M. Banks | Ship Mind |
| Dillinger(Dillinger, N.L.) — Starship Troopers | Starship Troopers | Robert A. Heinlein | Deserter / executed criminal |
| Dimak — Ender's Game | Ender's Game | Orson Scott Card | MinCol staff |
| Director Clemons(Norman Clemons, Director Norman Clemons) — The Calculating Stars | The Calculating Stars | Mary Robinette Kowal | actantial:sender |
| Director of the CIA — Understand | Understand | Ted Chiang | Intelligence head |
| Divlab Clerk — The Dispossessed | The Dispossessed | Ursula K. Le Guin | Administrator |
| Dixon — Agency | Agency | William Gibson | Drone manufacturer/Delivery |
| Diziet Sma(Sma, Dizzy) — Use of Weapons | Use of Weapons | Iain M. Banks | Culture representative |
| Do Campo — Starship Troopers | Starship Troopers | Robert A. Heinlein | minor |
| Dobb — A Perfect Vacuum | A Perfect Vacuum | Stanislaw Lem | Experimenter and author |
| Doc Wilson — The Forever War | The Forever War | Joe Haldeman | ship's doctor |
| Doctor — The Snow Queen | The Snow Queen | Joan D. Vinge | minor/coerced |
| Doctor Kimoe(Kimoe) — The Dispossessed | The Dispossessed | Ursula K. Le Guin | Ship's Doctor |
| Doctor Popichal — De Impossibilitate Vitae / De Impossibilitate Prognoscendi | De Impossibilitate Vitae / De Impossibilitate Prognoscendi | Stanislaw Lem | Surgeon Kouska's colleague |
| Doctors(doctor) — What's Expected of Us | What's Expected of Us | Ted Chiang | Observers/Interveners |
| Dodderont Debilitus — The Cyberiad | The Cyberiad | Stanislaw Lem | Dream persona |
| Dog Fucker(Sukrit Kamsing) — The Windup Girl | The Windup Girl | Paolo Bacigalupi | Dung Lord's intermediary |
| Dogias(Letitia, Letitia Dogias) — Ammonite | Ammonite | Nicola Griffith | Technician; storm-sensitive |
| Doherty(Lloyd Doherty) — Forever Peace | Forever Peace | Joe Haldeman | helper |
| Dol — The Years of Rice and Salt | The Years of Rice and Salt | Kim Stanley Robinson | Hindu interlocutor |
| Dom(Endomandiovizamarondeyaso) — Foundation's Edge | Foundation's Edge | Isaac Asimov | actantial:sender |
| Dom Cristão(the Ceifeiro) — Speaker for the Dead | Speaker for the Dead | Orson Scott Card | Head of the Filhos monastic order |
| Dom Paulo(the abbot, Father Abbot, Paulo) — A Canticle for Leibowitz | A Canticle for Leibowitz | Walter M. Miller, Jr. | Authority/Mediator |
| Dominic — Perhaps the Stars | Perhaps the Stars | Ada Palmer | Wounded follower |
| Dominic Seneschal(Dominic) — Seven Surrenders | Seven Surrenders | Ada Palmer | Servant to Jehovah and enemy of Madame |
| Dominic Seneschal(Dominic) — The Will to Battle | The Will to Battle | Ada Palmer | Servant of Jehovah, Acting Chief Director of Mitsubishi |
| Dominic Seneschal(Dominic, Canis, virile Dominic) — Too Like the Lightning | Too Like the Lightning | Ada Palmer | Investigator / Sensayer |
| Dominic Wexler(Lieutenant Wexler, Wex-ler) — Take Back Plenty | Take Back Plenty | Colin Greenland | USAF liaison officer (flashback) |
| don Alejandro — The Form of the Sword | The Form of the Sword | Jorge Luis Borges | Patriarch and leader of the Congress |
| don Alejandro — Tlön, Uqbar, Orbis Tertius | Tlön, Uqbar, Orbis Tertius | Jorge Luis Borges | Leader of the Congress |
| don Eliseo Amaro(don Eliseo) — The Form of the Sword | The Form of the Sword | Jorge Luis Borges | Gang Member |
| don Elíseo Amaro — Tlön, Uqbar, Orbis Tertius | Tlön, Uqbar, Orbis Tertius | Jorge Luis Borges | Gang member |
| Don Herbert(Mr. Wizard, Captain Herbert) — The Calculating Stars | The Calculating Stars | Mary Robinette Kowal | helper |
| Dona Cristã(the Aradora) — Speaker for the Dead | Speaker for the Dead | Orson Scott Card | Head of the Filhos monastic order |
| Donald Hogan(Donald, Donald Hogan Mark I, Donald Hogan Mark II +3) — Stand on Zanzibar | Stand on Zanzibar | John Brunner | Covert operative posing as journalist |
| Donel — Hyperion | Hyperion | Dan Simmons | helper |
| Donna Kelly — The Coral Bones | The Coral Bones | Jynne Martin | Absent figure / reef obsessive |
| Donor from Dorset — Never Let Me Go | Never Let Me Go | Kazuo Ishiguro | Donor patient |
| Dorcas — Stranger in a Strange Land | Stranger in a Strange Land | Robert A. Heinlein | Member of Harshaw's household |
| Doreen — Blackout/All Clear | Blackout/All Clear | Connie Willis | supporting |
| Doreen MacKenzie — Gateway | Gateway | Frederik Pohl | minor |
| Dorotea — Pattern Recognition | Pattern Recognition | William Gibson | Double agent / Blue Ant employee |
| Dorothea Morrell(Dr. Morrell) — Omphalos | Omphalos | Ted Chiang | Narrator and archaeologist |
| Dorothy L. Sayers — The Approach to Al-Mu'tasim | The Approach to Al-Mu'tasim | Jorge Luis Borges | Author |
| Dors Venabili(Jenat Korsan, Seldon's Tiger, Tiger Woman) — The Foundation Trilogy | The Foundation Trilogy | Isaac Asimov | Robot / Hari's deceased wife, reactivated |
| Douglas — Blackout/All Clear | Blackout/All Clear | Connie Willis | Oxford historian (likely Mary/another alias) |
| Dovid Sussman — The Yiddish Policemen's Union | The Yiddish Policemen's Union | Michael Chabon | minor antagonist |
| Dr Beckett(L. C. Beckett, Dr L. C. Beckett) — Lost Futures | Lost Futures | Lisa Tuttle | alternate self / imagined persona |
| Dr Burckhardt — The Separation | The Separation | Christopher Priest | actantial:sender/helper |
| Dr. Agnew(Lieutenant Agnew) — Stranger in a Strange Land | Stranger in a Strange Land | Robert A. Heinlein | Lost crewman |
| Dr. Aragones — Mirror Dance | Mirror Dance | Lois McMaster Bujold | Physician |
| Dr. Archibald Messenger(Messenger) — Solaris | Solaris | Stanislaw Lem | Commission Member |
| Dr. Ashbourne(Ashbourne) — Stories of Your Life and Others | Stories of Your Life and Others | Ted Chiang | Nomenclator |
| Dr. Brush — Stranger in a Strange Land | Stranger in a Strange Land | Robert A. Heinlein | Minor character / plot device |
| Dr. Buchbinder — The Yiddish Policemen's Union | The Yiddish Policemen's Union | Michael Chabon | minor figure / conspiracy fringe |
| Dr. Carlisle Perera(Dr Perera) — Rendezvous with Rama | Rendezvous with Rama | Arthur C. Clarke | Rama Committee scientist |
| Dr. Chan — The Moon Is a Harsh Mistress | The Moon Is a Harsh Mistress | Robert A. Heinlein | Diplomatic contact on Earth |
| Dr. de Shriver — The Uplift War | The Uplift War | David Brin | Chim physician, head of gorilla care team |
| Dr. Eduardo Zimmermann(Zimmermann, Dr. Zimmermann) — The Form of the Sword | The Form of the Sword | Jorge Luis Borges | Historian |
| Dr. Eduardo Zimmermann — Tlön, Uqbar, Orbis Tertius | Tlön, Uqbar, Orbis Tertius | Jorge Luis Borges | Historian / Rival |
| Dr. Foster — The Forever War | The Forever War | Joe Haldeman | ship's doctor |
| Dr. Henri — Barrayar | Barrayar | Lois McMaster Bujold | helper |
| Dr. Ian Combay — Non Serviam | Non Serviam | Stanislaw Lem | Colleague |
| Dr. Isidro Figueroa — Tlön, Uqbar, Orbis Tertius | Tlön, Uqbar, Orbis Tertius | Jorge Luis Borges | Protagonist / Painter |
| Dr. Janssen — Omphalos | Omphalos | Ted Chiang | Archaeologist |
| Dr. Jeems(Jeems) — The Demolished Man | The Demolished Man | Alfred Bester | supporting |
| Dr. Jo Marroni(Jo) — The Coral Bones | The Coral Bones | Jynne Martin | Cephalopod expert |
| Dr. Johnson — The Approach to Al-Mu'tasim | The Approach to Al-Mu'tasim | Jorge Luis Borges | Historical Figure |
| Dr. Juan Francisco Amaro — The Sect of the Phoenix | The Sect of the Phoenix | Jorge Luis Borges | Acquaintance of the narrator |
| Dr. Marcelo Yarmolinsky — Death and the Compass | Death and the Compass | Jorge Luis Borges | Victim |
| Dr. Morrell — Exhalation | Exhalation | Ted Chiang | Archaeologist |
| Dr. Nathan McCullough(Nathan, Mina, Mr. Dahl +1) — Exhalation | Exhalation | Ted Chiang | Thief / Believer |
| Dr. Navio — Speaker for the Dead | Speaker for the Dead | Orson Scott Card | minor character |
| Dr. Nelson(Sven) — Stranger in a Strange Land | Stranger in a Strange Land | Robert A. Heinlein | Medical authority / minor opponent |
| Dr. Raphael Corning — Stand on Zanzibar | Stand on Zanzibar | John Brunner | State Department synthesist |
| Dr. Rau — The Yiddish Policemen's Union | The Yiddish Policemen's Union | Michael Chabon | Minor |
| Dr. Ritter — Barrayar | Barrayar | Lois McMaster Bujold | helper |
| Dr. Shea — Understand | Understand | Ted Chiang | Neurologist-in-chief |
| Dr. Singh — Hyperion | Hyperion | Dan Simmons | Physician |
| Dr. Soo(Dr. Elayne Soo) — The Uplift War | The Uplift War | David Brin | actantial:helper |
| Dr. Stap — Use of Weapons | Use of Weapons | Iain M. Banks | Underground doctor |
| Dr. Stephen Albert — The Garden of Forking Paths | The Garden of Forking Paths | Jorge Luis Borges | Eminent Sinologist |
| Dr. Taka — The Uplift War | The Uplift War | David Brin | Minor character / Uplift scientist |
| Dr. Thackery Lambshead(Lambshead) — Dacey's Patent Automatic Nanny | Dacey's Patent Automatic Nanny | Ted Chiang | Consulting physician |
| Dr. Thackery Lambshead — Exhalation | Exhalation | Ted Chiang | Consulting Doctor |
| Dr. Wells — Cyteen | Cyteen | C. J. Cherryh | actantial:opponent |
| Dr. Winthrop(Winthrop) — The Form of the Sword | The Form of the Sword | Jorge Luis Borges | Academic Chairman |
| Dr. X — The Diamond Age | The Diamond Age | Neal Stephenson | sender/ideologue |
| Dr. Yentzicus(creator of the famous oculo-oscular feel theory) — The Fourth Sally or How Trurl Built a Femfatalatron | The Fourth Sally or How Trurl Built a Femfatalatron | Stanislaw Lem | Referenced academic |
| Dr. Yu Tsun(Yu Tsun) — The Circular Ruins | The Circular Ruins | Jorge Luis Borges | Spy / Former professor |
| Dr. Yu Tsun — The Form of the Sword | The Form of the Sword | Jorge Luis Borges | Spy, former professor |
| Dr. Yu Tsun — The Garden of Forking Paths | The Garden of Forking Paths | Jorge Luis Borges | Narrator and Protagonist |
| Drayta — Exhalation | Exhalation | Ted Chiang | Sophonce digient |
| Dred — Gateway | Gateway | Frederik Pohl | crewmate |
| Droctulft — The Circular Ruins | The Circular Ruins | Jorge Luis Borges | Warrior |
| Droctulft — Tlön, Uqbar, Orbis Tertius | Tlön, Uqbar, Orbis Tertius | Jorge Luis Borges | Warrior |
| Drodin — The City & The City | The City & The City | China Miéville | Dissident |
| Drone — Excession | Excession | Iain M. Banks | Companion |
| Droushnakovi(Drou, Droushie) — Barrayar | Barrayar | Lois McMaster Bujold | helper/bodyguard |
| Du Gange — The Sect of the Phoenix | The Sect of the Phoenix | Jorge Luis Borges | Medieval lexicographer (cited source) |
| Dua(Left-Em, baby-mid) — The Gods Themselves | The Gods Themselves | Isaac Asimov | Emotional triad member; intellectual outlier |
| Dua's Parental(Daddy) — The Gods Themselves | The Gods Themselves | Isaac Asimov | minor |
| Duchesse — Gruppenfuhrer Louis XVI | Gruppenfuhrer Louis XVI | Stanislaw Lem | Courtier / former prostitute |
| Duchesse de Clicot — A Perfect Vacuum | A Perfect Vacuum | Stanislaw Lem | Courtier / Former Prostitute |
| Due de Salignac — Gruppenfuhrer Louis XVI | Gruppenfuhrer Louis XVI | Stanislaw Lem | Courtier |
| Duffy Wyg&(Duffy) — The Demolished Man | The Demolished Man | Alfred Bester | supporting |
| Duke(Cannibal) — Stranger in a Strange Land | Stranger in a Strange Land | Robert A. Heinlein | Handyman and water-brother |
| Duke Leto Atreides(el Duque, mi Señor el Duque, Duque Leto +3) — Dune | Dune | Frank Herbert | Daughter of Leto and Jessica |
| Duke of Kent — The Separation | The Separation | Christopher Priest | Minor figure |
| Duncan Idaho(Idaho, Duncan) — Dune | Dune | Frank Herbert | helper |
| Dunworthy(Mr. Dunworthy, James) — Doomsday Book | Doomsday Book | Connie Willis | Protagonist (2054 strand); Kivrin's mentor |
| Dushwha — The Stone Sky | The Stone Sky | N. K. Jemisin | helper (deep past) |
| Dutch Bamburger(Dutch) — Starship Troopers | Starship Troopers | Robert A. Heinlein | Experienced trooper / Rico's assigned mentor on Klendathu drop |
| Dy Baocia — Paladin of Souls | Paladin of Souls | Lois McMaster Bujold | secondary |
| Dy Cabon(Learned dy Cabon, the divine, the fat divine) — Paladin of Souls | Paladin of Souls | Lois McMaster Bujold | helper |
| Dy Ferrej(Ser dy Ferrej) — Paladin of Souls | Paladin of Souls | Lois McMaster Bujold | opponent |
| Easter(Eostre) — American Gods | American Gods | Neil Gaiman | helper/ally |
| Ebenezer Bogle — Tlön, Uqbar, Orbis Tertius | Tlön, Uqbar, Orbis Tertius | Jorge Luis Borges | Servant/Accomplice |
| Eccentric Shoot Them Later(Shoot Them Later) — Excession | Excession | Iain M. Banks | Ship Mind |
| Ed Hammer III(Hammer) — A Perfect Vacuum | A Perfect Vacuum | Stanislaw Lem | President of Being Inc. |
| Ed Hammer III(Hammer) — Being Inc. | Being Inc. | Stanislaw Lem | President of Being Inc. |
| EDAN 197 — Non Serviam | Non Serviam | Stanislaw Lem | Historical personoid thinker |
| Eddy — Mona Lisa Overdrive | Mona Lisa Overdrive | William Gibson | Mona's pimp and manager |
| Edki — The Fifth Season | The Fifth Season | N.K. Jemisin | Guardian |
| Edmund — The Ministry for the Future | The Ministry for the Future | Kim Stanley Robinson | Wealthy elite |
| Edmund Dacey — Exhalation | Exhalation | Ted Chiang | Father of Edmund |
| Edmund Spenser(Spenser) — The Approach to Al-Mu'tasim | The Approach to Al-Mu'tasim | Jorge Luis Borges | Author |
| Edouard(Monsignor Edouard) — Hyperion | Hyperion | Dan Simmons | Absent confidant |
| Eduardo Nelson — The Form of the Sword | The Form of the Sword | Jorge Luis Borges | Younger brother |
| Eduardo Zimmermann(Dr. Zimmermann) — The Circular Ruins | The Circular Ruins | Jorge Luis Borges | Historian |
| Edward — The Peripheral | The Peripheral | William Gibson | Tech support, maker |
| Edward Blount — Queen of the States | Queen of the States | Lisa Goldstein | Publisher / minor character |
| Edward Delaney(William Delaney, Joseph Marvin, Joseph Morris +1) — Tlön, Uqbar, Orbis Tertius | Tlön, Uqbar, Orbis Tertius | Jorge Luis Borges | Ward boss / Gang leader |
| Edward FitzGerald — The Approach to Al-Mu'tasim | The Approach to Al-Mu'tasim | Jorge Luis Borges | Translator |
| Edward Maitland, Lord Fieldhurst(Lord Fieldhurst, the earl, Fieldhurst) — Seventy-Two Letters | Seventy-Two Letters | Ted Chiang | President of the Royal Society, zoologist |
| Edward Ostermann(Monk Eastman, Eastman) — The Circular Ruins | The Circular Ruins | Jorge Luis Borges | Gangster |
| Efor — The Dispossessed | The Dispossessed | Ursula K. Le Guin | Servant |
| Eight Antidote(the Cure, little spy, imperial heir +1) — A Desolation Called Peace | A Desolation Called Peace | Arkady Martine | Imperial prince and apprentice observer |
| Eight Loop — A Desolation Called Peace | A Desolation Called Peace | Arkady Martine | minister |
| Eighteen Chisel — A Desolation Called Peace | A Desolation Called Peace | Arkady Martine | Fleet officer; intelligence analyst |
| Eileen(Merope, Eileen Ward) — Blackout/All Clear | Blackout/All Clear | Connie Willis | Protagonist / stranded historian |
| Eino Kaikki — Non Serviam | Non Serviam | Stanislaw Lem | Referenced philosopher |
| Ektor Papadelias(Papa, Commissioner General) — Perhaps the Stars | Perhaps the Stars | Ada Palmer | Commissioner General |
| Ela — Speaker for the Dead | Speaker for the Dead | Orson Scott Card | Novinha's eldest daughter, amateur xenobiologist |
| Eleanor Hardy — Dacey's Patent Automatic Nanny | Dacey's Patent Automatic Nanny | Ted Chiang | Edmund's biological mother |
| Elena Bothari-Jesek(Captain Bothari-Jesek) — Mirror Dance | Mirror Dance | Lois McMaster Bujold | Dendarii captain / confidante |
| Elencher drone(soldier drone) — Excession | Excession | Iain M. Banks | Military drone |
| Elethiomel(Elethiomel the Chairmaker) — Use of Weapons | Use of Weapons | Iain M. Banks | Childhood rival |
| Eletra(Casualty One) — Network Effect | Network Effect | Martha Wells | Corporate survivor / ambiguous figure |
| Eleven Lathe — A Desolation Called Peace | A Desolation Called Peace | Arkady Martine | historical figure |
| Eleven Laurel(Undersecretary) — A Desolation Called Peace | A Desolation Called Peace | Arkady Martine | Third Undersecretary of the Third Palm, Ministry of War |
| Elihu(Elihu Masters) — Stand on Zanzibar | Stand on Zanzibar | John Brunner | Diplomat / intermediary |
| Elijah(Elijah the Prophet) — The Yiddish Policemen's Union | The Yiddish Policemen's Union | Michael Chabon | trickster/minor |
| Eliot — Snow Crash | Snow Crash | Neal Stephenson | helper |
| Eliwys(Lady Eliwys) — Doomsday Book | Doomsday Book | Connie Willis | Medieval noblewoman; helper |
| Elizabeth(Elizabeth Finkle-McGraw) — The Diamond Age | The Diamond Age | Neal Stephenson | Schoolfellow/Duke's granddaughter |
| Elizabeth Boudry(Boudry woman) — The Windup Girl | The Windup Girl | Paolo Bacigalupi | actantial:receiver |
| Elli Quinn(Captain Quinn) — Mirror Dance | Mirror Dance | Lois McMaster Bujold | Senior Dendarii officer / Miles's companion |
| Ellie Frazer — Forever Peace | Forever Peace | Joe Haldeman | helper |
| Elma — The Martian Chronicles | The Martian Chronicles | Ray Bradbury | minor |
| Elmore — All Tomorrow's Parties | All Tomorrow's Parties | William Gibson | Driver |
| Elsevier(Elsie, Obedience) — The Snow Queen | The Snow Queen | Joan D. Vinge | Helper / ship captain |
| Elsie — The Uplift War | The Uplift War | David Brin | Chim lieutenant, bespectacled middle-aged chimmie |
| Eluti — Tower of Babylon | Tower of Babylon | Ted Chiang | Elamite miner |
| Ember Balin(Dr. Balin, Balin) — Too Like the Lightning | Too Like the Lightning | Ada Palmer | Psychiatrist |
| Emerson D'Anite — Startide Rising | Startide Rising | David Brin | Human crew member |
| Emiko(the windup girl, windup girl, heechy-keechy +1) — The Windup Girl | The Windup Girl | Paolo Bacigalupi | Japanese-engineered New Person stranded in Bangkok |
| Emil Schering — Three Versions of Judas | Three Versions of Judas | Jorge Luis Borges | Translator |
| Emilio Sandoz(Father Sandoz, Dr. Sandoz, Milio +4) — The Sparrow | The Sparrow | Mary Doria Russell | Protagonist; sole mission survivor |
| Eminent mathematician — Odysseus of Ithaca | Odysseus of Ithaca | Stanislaw Lem | Expert Consultant |
| emissary — Excession | Excession | Iain M. Banks | Messenger |
| Emma Fother — Gateway | Gateway | Frederik Pohl | supporting |
| Emma Zunz — The Form of the Sword | The Form of the Sword | Jorge Luis Borges | Avenger |
| Emma Zunz — Tlön, Uqbar, Orbis Tertius | Tlön, Uqbar, Orbis Tertius | Jorge Luis Borges | Avenger |
| Emperor Chia-Ch'ing — The Form of the Sword | The Form of the Sword | Jorge Luis Borges | Emperor |
| Emperor Ezar(Ezar Vorbarra) — Barrayar | Barrayar | Lois McMaster Bujold | background |
| Emperor Gregor(Prince Gregor, the boy emperor) — Barrayar | Barrayar | Lois McMaster Bujold | actantial object |
| Emperor Klayus — The Foundation Trilogy | The Foundation Trilogy | Isaac Asimov | Figurehead Emperor |
| Emperor Maximillion — The Cyberiad | The Cyberiad | Stanislaw Lem | Sovereign |
| Emperor Maximillion — The Third Sally or The Dragons of Probability | The Third Sally or The Dragons of Probability | Stanislaw Lem | Ruler of Prestopondora |
| Emperor Shaddam IV(Padishah Emperor) — Dune | Dune | Frank Herbert | opponent |
| Emperor Turbulon(Turbulon) — The First Sally or The Trap of Gargantius | The First Sally or The Trap of Gargantius | Stanislaw Lem | Historical monarch |
| Employer on Nepiy(the woman in charge) — Stars in My Pocket Like Grains of Sand | Stars in My Pocket Like Grains of Sand | Samuel R. Delany | Employer |
| Ender(Andrew Wiggin, Speaker Andrew, the Xenocide +4) — Speaker for the Dead | Speaker for the Dead | Orson Scott Card | Speaker for the Dead, protagonist |
| English grandmother — The Form of the Sword | The Form of the Sword | Jorge Luis Borges | Grandmother |
| Englishwoman(Indian woman) — The Form of the Sword | The Form of the Sword | Jorge Luis Borges | Captive, chieftain's wife |
| Enrique Beltran — Exhalation | Exhalation | Ted Chiang | Forum user |
| Ensign Grover — Redshirts | Redshirts | John Scalzi | Unnamed ensign / expendable crew |
| Erens — Use of Weapons | Use of Weapons | Iain M. Banks | Crew Member |
| Eric Cooper(Gerald, Eric) — Fledgling | Fledgling | Octavia E. Butler | Westfall Symbiont |
| Eric Einarsson(E.E., Einarsson) — The Form of the Sword | The Form of the Sword | Jorge Luis Borges | Academic |
| Eric Ellerman — Stand on Zanzibar | Stand on Zanzibar | John Brunner | Vignette Character |
| Erica — The Coral Bones | The Coral Bones | Jynne Martin | Witness/tourist |
| Erich Palatzky(Duc de Montbazon) — Gruppenfuhrer Louis XVI | Gruppenfuhrer Louis XVI | Stanislaw Lem | Taudlitz's confidant |
| Erik Erfjord(Erfjord) — Three Versions of Judas | Three Versions of Judas | Jorge Luis Borges | Danish Hebrew scholar |
| Erik Erfjord(Gunnar Erfjord) — Tlön, Uqbar, Orbis Tertius | Tlön, Uqbar, Orbis Tertius | Jorge Luis Borges | Scholar/Secret Society Member |
| Erik Lönnrot — Death and the Compass | Death and the Compass | Jorge Luis Borges | Detective |
| Erik Lönnrot(Lönnrot) — The Form of the Sword | The Form of the Sword | Jorge Luis Borges | Detective |
| Erik Lönnrot — Tlön, Uqbar, Orbis Tertius | Tlön, Uqbar, Orbis Tertius | Jorge Luis Borges | Detective |
| Erika — Lost Futures | Lost Futures | Lisa Tuttle | Laurel's adopted daughter |
| Ernesto — New York 2140 | New York 2140 | Kim Stanley Robinson | Deli owner |
| Ernst Palast — Death and the Compass | Death and the Compass | Jorge Luis Borges | Journalist |
| Esmerdis el mago(Esmerdis) — Ficciones (Tlön, Uqbar, Orbis Tertius) | Ficciones (Tlön, Uqbar, Orbis Tertius) | Jorge Luis Borges | Historical figure in Uqbar |
| Esmerine — The Years of Rice and Salt | The Years of Rice and Salt | Kim Stanley Robinson | Bahram's wife, Khalid's daughter |
| Esni — The Stone Sky | The Stone Sky | N. K. Jemisin | minor helper |
| Essie Tregowan(Essie Richardson) — American Gods | American Gods | Neil Gaiman | Interlude protagonist |
| Essun(you, Syenite, Syen +2) — The Fifth Season | The Fifth Season | N.K. Jemisin | Fulcrum-trained orogene, partner to Innon and Alabaster |
| Essun(Syenite, Damaya, you) — The Stone Sky | The Stone Sky | N. K. Jemisin | Protagonist (Essun storyline) / addressee of Hoa's narration |
| Estelle — The Forever War | The Forever War | Joe Haldeman | medical officer |
| Ester-Malke — The Yiddish Policemen's Union | The Yiddish Policemen's Union | Michael Chabon | helper/supporting |
| Esterhazy — Barrayar | Barrayar | Lois McMaster Bujold | actantial helper |
| Esther — Fledgling | Fledgling | Octavia E. Butler | Symbiont |
| Estraven(Therem Harth rem ir Estraven, the Traitor, the King's Ear +6) — The Left Hand of Darkness | The Left Hand of Darkness | Ursula K. Le Guin | Exiled Prime Minister / POV narrator |
| Estwald — The Gods Themselves | The Gods Themselves | Isaac Asimov | Hard One scientist; emergent identity of the triad |
| Ethan — Stories of Your Life and Others | Stories of Your Life and Others | Ted Chiang | Preacher / Visitation witness |
| Ethan Mead(Claire) — Hell Is the Absence of God | Hell Is the Absence of God | Ted Chiang | Librarian and Witness |
| Ethnarch Kerian — Use of Weapons | Use of Weapons | Iain M. Banks | Tyrant |
| Eudoro Acevedo — Tlön, Uqbar, Orbis Tertius | Tlön, Uqbar, Orbis Tertius | Jorge Luis Borges | Narrator / Time traveler |
| Eugene(Major Lindholm) — The Calculating Stars | The Calculating Stars | Mary Robinette Kowal | supporting |
| Eunice(Untethered Noetic Irregular Support System, U-N-I-S-S, E) — Agency | Agency | William Gibson | Artificial Intelligence |
| Euphorius Cloy — The Third Sally or The Dragons of Probability | The Third Sally or The Dragons of Probability | Stanislaw Lem | Inventor |
| Eureka — Too Like the Lightning | Too Like the Lightning | Ada Palmer | Cartesian set-set |
| Evans — Echopraxia | Echopraxia | Peter Watts | Crew member |
| Evil King — The Form of the Sword | The Form of the Sword | Jorge Luis Borges | Usurper King |
| Evon Vorhalas(Vorhalas) — Barrayar | Barrayar | Lois McMaster Bujold | opponent |
| Ewdrad B. Tynar(M. Tynar) — The Fall of Hyperion | The Fall of Hyperion | Dan Simmons | actantial:helper |
| Excelsius(Excelsius the Tartarian) — The Seventh Sally or How Trurl's Own Perfection Led to No Good | The Seventh Sally or How Trurl's Own Perfection Led to No Good | Stanislaw Lem | antagonist/recipient |
| Ezra Buckley(Buckley) — Ficciones (Tlön, Uqbar, Orbis Tertius) | Ficciones (Tlön, Uqbar, Orbis Tertius) | Jorge Luis Borges | Ascetic millionaire |
| Ezra Buckley — The Circular Ruins | The Circular Ruins | Jorge Luis Borges | Reclusive millionaire and demiurge |
| Ezra Buckley — Tlön, Uqbar, Orbis Tertius | Tlön, Uqbar, Orbis Tertius | Jorge Luis Borges | Benefactor |
| Ezra Winthrop — Tlön, Uqbar, Orbis Tertius | Tlön, Uqbar, Orbis Tertius | Jorge Luis Borges | Professor |
| Fabrisi(Peter Fabrisi) — Division by Zero | Division by Zero | Ted Chiang | Renee's colleague |
| Fabrisi — Stories of Your Life and Others | Stories of Your Life and Others | Ted Chiang | Colleague |
| Fairchild(Lieutenant Fairchild) — Blackout/All Clear | Blackout/All Clear | Connie Willis | FANY unit member |
| Fakir — Tlön, Uqbar, Orbis Tertius | Tlön, Uqbar, Orbis Tertius | Jorge Luis Borges | Painter/Prisoner |
| False Garuda(Remade) — Perdido Street Station | Perdido Street Station | China Miéville | Freak show exhibit |
| Fang — The Garden of Forking Paths | The Garden of Forking Paths | Jorge Luis Borges | Fictional character |
| Farad Sinter — The Foundation Trilogy | The Foundation Trilogy | Isaac Asimov | Chief Commissioner of General Security / antagonist |
| Farïd al-dïn Attar(Farïd al-dïn Abï Hämid Muhammad ben Ibrahim, Attãr, perfumer) — The Approach to Al-Mu'tasim | The Approach to Al-Mu'tasim | Jorge Luis Borges | Persian mystic poet |
| Fate Amenable To Change(Fate) — Excession | Excession | Iain M. Banks | Culture craft |
| Fate Ravenglass(Fate) — The Snow Queen | The Snow Queen | Joan D. Vinge | Secret sibyl and maskmaker in Carbuncle |
| Father(Captain Holliman) — The Coral Bones | The Coral Bones | Jynne Martin | Judith's father / ship captain |
| Father Lenar Hoyt(Hoyt) — Hyperion | Hyperion | Dan Simmons | Pilgrim / priest / first storyteller |
| Father Lenar Hoyt(Father Hoyt) — The Fall of Hyperion | The Fall of Hyperion | Dan Simmons | Pilgrim; Jesuit priest carrying two cruciforms |
| Father Paul Duré(Duré) — Hyperion | Hyperion | Dan Simmons | Jesuit priest/journal narrator |
| Father Paul Duré(Duré, Pope Teilhard I) — The Fall of Hyperion | The Fall of Hyperion | Dan Simmons | Jesuit priest; cruciform bearer |
| Father Roche(Roche) — Doomsday Book | Doomsday Book | Connie Willis | Medieval village priest |
| Fatimah Akurgal(Fatimah) — Air | Air | Geoff Ryman | opponent |
| Faust's devil — Rien du tout, ou la consequence | Rien du tout, ou la consequence | Stanislaw Lem | Fictional character |
| Faxe(the Weaver, the Foreteller of Otherhord Fastness) — The Left Hand of Darkness | The Left Hand of Darkness | Ursula K. Le Guin | Handdara Weaver / Foreteller |
| Faye — The Coral Bones | The Coral Bones | Jynne Martin | helper |
| Felipe Reyes(Felipe) — The Sparrow | The Sparrow | Mary Doria Russell | Jesuit professor of comparative religion; Sandoz's childhood friend |
| Felix Faust(Headmaster, Onkel, Uncle) — Perhaps the Stars | Perhaps the Stars | Ada Palmer | Headmaster of the Brillist Institute |
| Felix Faust(Headmaster) — Too Like the Lightning | Too Like the Lightning | Ada Palmer | Headmaster of the Brillist Institute |
| Felix Radcliffe(Felix) — The Lifecycle of Software Objects | The Lifecycle of Software Objects | Ted Chiang | Xenotherian hobbyist |
| Fellyr — Ammonite | Ammonite | Nicola Griffith | Secondary character / Briogannon connection |
| Ferda dy Gura(officer-dedicat) — Paladin of Souls | Paladin of Souls | Lois McMaster Bujold | helper |
| Ferdaz — The Dispossessed | The Dispossessed | Ursula K. Le Guin | Old PDC adviser |
| Fergus Kilpatrick(the traitor-hero) — The Circular Ruins | The Circular Ruins | Jorge Luis Borges | Irish rebel leader |
| Fergus Kilpatrick — The Form of the Sword | The Form of the Sword | Jorge Luis Borges | Irish rebel leader and traitor |
| Fergus Kilpatrick(the traitor-hero, the condemned man, the protagonist) — Theme of the Traitor and the Hero | Theme of the Traitor and the Hero | Jorge Luis Borges | Leader of conspirators / Traitor |
| Fergus Kilpatrick — Tlön, Uqbar, Orbis Tertius | Tlön, Uqbar, Orbis Tertius | Jorge Luis Borges | Leader / Traitor / Hero |
| Fermín Eguren(Eguren) — The Circular Ruins | The Circular Ruins | Jorge Luis Borges | Congress delegate |
| Fernández Irala(Fernández Kraal, Kraal) — The Circular Ruins | The Circular Ruins | Jorge Luis Borges | Poet and Congress delegate |
| Fernández Irala(Irala) — The Form of the Sword | The Form of the Sword | Jorge Luis Borges | Congress member |
| Ferreira — Ender's Game | Ender's Game | Orson Scott Card | Hegemony intelligence officer |
| Ferrix(Prince Ferrix, Myamlak) — The Cyberiad | The Cyberiad | Stanislaw Lem | Heir apparent to the Ionid throne |
| Feyd-Rautha Harkonnen(el Barón, mi Señor Harkonnen, the Baron +6) — Dune | Dune | Frank Herbert | Antagonist, head of House Harkonnen |
| Fiben Bolger(Trog, Mr. Bluecard, Fiben +1) — The Uplift War | The Uplift War | David Brin | Neo-chimpanzee scout and resistance fighter |
| Fichte — Die Kultur als Fehler | Die Kultur als Fehler | Stanislaw Lem | Historical Philosopher |
| Fido(Rat Thing, Semi-Autonomous Guard Unit #A-367, SemiAutonomous Guard Unit #A-367) — Snow Crash | Snow Crash | Neal Stephenson | actantial:helper |
| Filistranorlry — Ringworld | Ringworld | Larry Niven | opponent |
| Finch — Doomsday Book | Doomsday Book | Connie Willis | Minor / Dunworthy's secretary |
| Finch — To Say Nothing of the Dog | To Say Nothing of the Dog | Connie Willis | Butler/undercover operative |
| Finn — Redshirts | Redshirts | John Scalzi | Dead crewman / Dream interlocutor |
| Finn(General Nielsen) — The Moon Is a Harsh Mistress | The Moon Is a Harsh Mistress | Robert A. Heinlein | military commander |
| Fion — Ammonite | Ammonite | Nicola Griffith | Echraidhe guard |
| Fiona(Fiona Hackworth) — The Diamond Age | The Diamond Age | Neal Stephenson | Schoolfellow/Hackworth's daughter |
| Fire(The manifold god) — The Circular Ruins | The Circular Ruins | Jorge Luis Borges | Deity |
| First — A Desolation Called Peace | A Desolation Called Peace | Arkady Martine | Alien contact individual |
| Fisheye — Snow Crash | Snow Crash | Neal Stephenson | helper |
| Fishkin — The Yiddish Policemen's Union | The Yiddish Policemen's Union | Michael Chabon | witness |
| Fitz — The Lifecycle of Software Objects | The Lifecycle of Software Objects | Ted Chiang | Digient |
| Five Agate — A Desolation Called Peace | A Desolation Called Peace | Arkady Martine | ezuazuacat |
| Fivetide Humidyear VII(Fivetide, Colonel Alien-Befriender) — Excession | Excession | Iain M. Banks | Affronter Diplomatic Force officer |
| Flapper — Stories of Your Life and Others | Stories of Your Life and Others | Ted Chiang | Heptapod alien |
| Flavius Josephus — The Sect of the Phoenix | The Sect of the Phoenix | Jorge Luis Borges | Ancient source (cited approvingly) |
| Fleet Sergeant Ho — Starship Troopers | Starship Troopers | Robert A. Heinlein | military recruiter |
| Fligler — The Yiddish Policemen's Union | The Yiddish Policemen's Union | Michael Chabon | opponent/enforcer |
| Flin — Excession | Excession | Iain M. Banks | Companion |
| Flores(Dizzy) — Starship Troopers | Starship Troopers | Robert A. Heinlein | trooper (wounded) |
| Florian(Florian AF-9979, F12, Florian II) — Cyteen | Cyteen | C. J. Cherryh | azi companion/POV character |
| Flynne Fisher(Hat trick, HaptRec, polt +4) — The Peripheral | The Peripheral | William Gibson | Protagonist, peripheral operator |
| Foix(Foix dy Gura) — Paladin of Souls | Paladin of Souls | Lois McMaster Bujold | helper |
| Fontaine(The old man, black man) — All Tomorrow's Parties | All Tomorrow's Parties | William Gibson | Pawn/watch shop owner |
| Fontaine — Virtual Light | Virtual Light | William Gibson | Bridge mechanic |
| Foo Moses Morris — The Moon Is a Harsh Mistress | The Moon Is a Harsh Mistress | Robert A. Heinlein | financial backer |
| Fordham — Blackout/All Clear | Blackout/All Clear | Connie Willis | Supporting / hospital ward companion |
| Foreign Caller — The City & The City | The City & The City | China Miéville | Informant |
| Foreman — The Dispossessed | The Dispossessed | Ursula K. Le Guin | Defense crew foreman |
| Former Programmer (unnamed woman) — Snow Crash | Snow Crash | Neal Stephenson | receiver |
| Fort — Blue Mars | Blue Mars | Kim Stanley Robinson | Actantial sender / mentor figure |
| Fort(William Fort) — Green Mars | Green Mars | Kim Stanley Robinson | Praxis CEO and mission sender |
| Foster(Archangel Foster, Blessed Foster, Reverend Foster) — Stranger in a Strange Land | Stranger in a Strange Land | Robert A. Heinlein | Deceased Fosterite founder |
| Fosyf Denche(Citizen Raughd, Citizen Fosyf) — Ancillary Sword | Ancillary Sword | Ann Leckie | Fosyf's daughter / local antagonist |
| Four Crocus — A Desolation Called Peace | A Desolation Called Peace | Arkady Martine | minor |
| Fourth Suitor(beau) — De Impossibilitate Vitae / De Impossibilitate Prognoscendi | De Impossibilitate Vitae / De Impossibilitate Prognoscendi | Stanislaw Lem | The nurse's suitor |
| Fracciterne(Hiveless Fracciterne) — The Will to Battle | The Will to Battle | Ada Palmer | Graylaw Spokesperson |
| Francis Quinn(Quinn) — I, Robot | I, Robot | Isaac Asimov | Political operator; antagonist |
| Francisco — Imago | Imago | Octavia E. Butler | Human elder |
| Francisco Ferrari(Ferrari) — The Form of the Sword | The Form of the Sword | Jorge Luis Borges | Gang Leader |
| Francisco Ferrari — Tlön, Uqbar, Orbis Tertius | Tlön, Uqbar, Orbis Tertius | Jorge Luis Borges | Gang leader |
| Francisco Flores — The South | The South | Jorge Luis Borges | ancestor |
| Franco — Pattern Recognition | Pattern Recognition | William Gibson | Operative/Thug |
| Frank(Frank Chalmers, Chalmers) — Blue Mars | Blue Mars | Kim Stanley Robinson | American political operator and co-leader |
| Frank(Jacob Salzman) — The Ministry for the Future | The Ministry for the Future | Kim Stanley Robinson | PTSD survivor and eco-terrorist |
| Frank Chalmers — Green Mars | Green Mars | Kim Stanley Robinson | Historical figure / suspected conspirator |
| Frank Chalmers(Chalmers) — Red Mars | Red Mars | Kim Stanley Robinson | Historical subject / First Hundred political operator |
| Frank Pearson(Pearson) — The Lifecycle of Software Objects | The Lifecycle of Software Objects | Ted Chiang | Representative from Exponential Appliances |
| Franklin — Forever Peace | Forever Peace | Joe Haldeman | supporting |
| Franklin — New York 2140 | New York 2140 | Kim Stanley Robinson | Boat pilot and trader |
| Franklin K. Clark(Frank) — The Separation | The Separation | Christopher Priest | Minor figure |
| Frans(Colonel Blimp) — New York 2140 | New York 2140 | Kim Stanley Robinson | Airship autopilot |
| Fred Hauser(Fred) — The Moon Is a Harsh Mistress | The Moon Is a Harsh Mistress | Robert A. Heinlein | Luna wheat farmer; meeting attendee |
| Fred Murdock(Murdock) — The Form of the Sword | The Form of the Sword | Jorge Luis Borges | Student / Librarian |
| Fred Murdock — Tlön, Uqbar, Orbis Tertius | Tlön, Uqbar, Orbis Tertius | Jorge Luis Borges | Student / Ethnographer |
| Freddie(Freddy) — Virtual Light | Virtual Light | William Gibson | Warbaby's jockey |
| Frederick Hallam — The Gods Themselves | The Gods Themselves | Isaac Asimov | antagonist |
| Frederick R. Waterford(the Commander) — The Handmaid's Tale | The Handmaid's Tale | Margaret Atwood | Historical figure/probable Commander |
| Freeman Ghenga(Spokesman Freeman Ghenga) — The Fall of Hyperion | The Fall of Hyperion | Dan Simmons | Ouster Tribunal spokesperson |
| Fremen (unnamed) — Dune | Dune | Frank Herbert | helper |
| Fromwest — The Years of Rice and Salt | The Years of Rice and Salt | Kim Stanley Robinson | herald/prophet |
| Frost(Mr. Frost) — Timescape | Timescape | Gregory Benford | Curator of the Institute for Astronomy |
| Fukumoto — Dawn | Dawn | Octavia E. Butler | Human survivor (mentioned) |
| Fukumoto(Fukumoto-san) — Imago | Imago | Octavia E. Butler | Human survivor |
| Fuwaad ibn Abbas(My lord, Narrator) — Exhalation | Exhalation | Ted Chiang | Traveler / Narrator |
| Fuwaad ibn Abbas — The Merchant and the Alchemist's Gate | The Merchant and the Alchemist's Gate | Ted Chiang | Protagonist and Narrator |
| Gaal Dornick — The Foundation Trilogy | The Foundation Trilogy | Isaac Asimov | Co-defendant |
| Gabbro — Ammonite | Ammonite | Nicola Griffith | Traveling companion |
| Gabriel(Gabe) — Dawn | Dawn | Octavia E. Butler | Human survivor and escape leader |
| Gabriel — Dreamsnake | Dreamsnake | Vonda N. McIntyre | secondary |
| Gabriel Harvey(Doctor Harvey) — Queen of the States | Queen of the States | Lisa Goldstein | Minor antagonist (offstage feud) |
| Gabriel Rinaldi(Gabriel, Gabe) — Imago | Imago | Octavia E. Butler | Human survivor |
| Gadlem(Commissar Gadlem) — The City & The City | The City & The City | China Miéville | Commissar in the Besźel police force |
| Gaewha(Antimony) — The Stone Sky | The Stone Sky | N. K. Jemisin | Tuner (Syl Anagist flashback) |
| Gailet Jones(Gailett, Gailet) — The Uplift War | The Uplift War | David Brin | Protagonist / urban resistance intellectual |
| Galen — Mirror Dance | Mirror Dance | Lois McMaster Bujold | Opponent (backstory) |
| Galen Chervil(Gally Chervil, Chervil boy) — The Demolished Man | The Demolished Man | Alfred Bester | Minor obstacle |
| Gallat(Conductor Gallat) — The Stone Sky | The Stone Sky | N. K. Jemisin | Antagonist / overseer (Syl Anagist flashback) |
| Galt — Adulthood Rites | Adulthood Rites | Octavia E. Butler | Raider |
| Galt — Imago | Imago | Octavia E. Butler | Human raider |
| Gamma — Hyperion | Hyperion | Dan Simmons | Bikura member |
| Ganagweh — The Years of Rice and Salt | The Years of Rice and Salt | Kim Stanley Robinson | Hodenosaunee acquaintance |
| Ganesha — Lord of Light | Lord of Light | Roger Zelazny | helper/opponent |
| Ganymede(Mariscal de la Trémoïlle, duke) — Perhaps the Stars | Perhaps the Stars | Ada Palmer | Mariscal of European-Humanist forces |
| Ganymede(Golden Ganymede, Duke, President +2) — Too Like the Lightning | Too Like the Lightning | Ada Palmer | Humanist President |
| Ganymede Jean-Louis de la Trémoïlle(Ganymede, President, The Duke President +2) — Seven Surrenders | Seven Surrenders | Ada Palmer | President of the Humanists |
| Ganymede Jean-Louis de la Trémoïlle(Ganymede, Duke) — The Will to Battle | The Will to Battle | Ada Palmer | Fallen President |
| Gao — The Years of Rice and Salt | The Years of Rice and Salt | Kim Stanley Robinson | Domestic companion |
| Garcin de Tassy — The Approach to Al-Mu'tasim | The Approach to Al-Mu'tasim | Jorge Luis Borges | Translator |
| Gargantius — The First Sally or The Trap of Gargantius | The First Sally or The Trap of Gargantius | Stanislaw Lem | Historical inventor/thinker |
| Garland(Inspector Garland) — Do Androids Dream of Electric Sheep? | Do Androids Dream of Electric Sheep? | Philip K. Dick | opponent |
| Garreth — Spook Country | Spook Country | William Gibson | Operative/Sniper |
| Garrett — Liking What You See: A Documentary | Liking What You See: A Documentary | Ted Chiang | Tamera's former boyfriend, student at Northrop |
| Garrett — Stories of Your Life and Others | Stories of Your Life and Others | Ted Chiang | Tamera's ex-boyfriend |
| Garrett — The Martian Chronicles | The Martian Chronicles | Ray Bradbury | opponent |
| Garrison — Pushing Ice | Pushing Ice | Alastair Reynolds | Bella's deceased partner |
| Gary Donnelly(Gary, Dr. Gary Donnelly, your dad) — Stories of Your Life and Others | Stories of Your Life and Others | Ted Chiang | Physicist |
| Gary Donnelly(Your father, Your dad, Dr. Gary Donnelly) — Story of Your Life | Story of Your Life | Ted Chiang | Physicist |
| Gates — Timescape | Timescape | Gregory Benford | Committee member |
| Gavrila — Forever Peace | Forever Peace | Joe Haldeman | opponent |
| Gawyn — Doomsday Book | Doomsday Book | Connie Willis | Medieval household knight; key information-holder |
| GCU Grey Area(slave-drone, Meatfucker) — Excession | Excession | Iain M. Banks | General Contact Unit |
| Ged — Perdido Street Station | Perdido Street Station | China Miéville | Acquaintance of Isaac |
| Gen — New York 2140 | New York 2140 | Kim Stanley Robinson | NYPD inspector |
| Gen — The Years of Rice and Salt | The Years of Rice and Salt | Kim Stanley Robinson | sender |
| Gendo-sama — The Windup Girl | The Windup Girl | Paolo Bacigalupi | Emiko's former Japanese owner (referenced) |
| General Botsford — The Forever War | The Forever War | Joe Haldeman | senior officer at Stargate |
| General Kallner(Major-general Kallner) — I, Robot | I, Robot | Isaac Asimov | Commander, Hyper Base |
| General Morpurgo(Morpurgo) — The Fall of Hyperion | The Fall of Hyperion | Dan Simmons | FORCE military commander |
| General Pracha(Chao Khun General Pracha) — The Windup Girl | The Windup Girl | Paolo Bacigalupi | Environment Ministry commander |
| General Thrale, C.I.E. — An Examination of the Work of Herbert Quain | An Examination of the Work of Herbert Quain | Jorge Luis Borges | Character in 'The Secret Mirror' |
| Genghis Khan — The Approach to Al-Mu'tasim | The Approach to Al-Mu'tasim | Jorge Luis Borges | Historical Conqueror |
| Genly Ai(Mr. Ai, the Envoy, First Mobile +3) — The Left Hand of Darkness | The Left Hand of Darkness | Ursula K. Le Guin | Ekumenical Envoy / primary narrator |
| Gentry — Mona Lisa Overdrive | Mona Lisa Overdrive | William Gibson | Hacker |
| George — Blue Mars | Blue Mars | Kim Stanley Robinson | Minor colonist |
| George — Never Let Me Go | Never Let Me Go | Kazuo Ishiguro | Assistant/Nurse |
| George(George Cowper, Master Cowper) — Queen of the States | Queen of the States | Lisa Goldstein | Secondary antagonist / reluctant conspirator |
| George — Red Mars | Red Mars | Kim Stanley Robinson | Survey team member |
| George Greggson(George) — Childhood's End | Childhood's End | Arthur C. Clarke | protagonist (Movement II) |
| Geraint — Among Others | Among Others | Jo Walton | minor / illustrative figure |
| Gerald Black — I, Robot | I, Robot | Isaac Asimov | Etheric physicist, Hyper Base |
| Gerald Phipps — Blackout/All Clear | Blackout/All Clear | Connie Willis | minor |
| Gerrel — Ammonite | Ammonite | Nicola Griffith | helper |
| Gerry — Stand on Zanzibar | Stand on Zanzibar | John Brunner | Urban everyman |
| Gestra — Excession | Excession | Iain M. Banks | Hermit/Caretaker |
| Ghost Bird(The double, The copy) — Acceptance | Acceptance | Jeff VanderMeer | Area X wanderer / Biologist's duplicate |
| Giambattista Marino(the new Homer, the new Dante) — Tlön, Uqbar, Orbis Tertius | Tlön, Uqbar, Orbis Tertius | Jorge Luis Borges | Poet |
| Gian Carlo Spallanzani — A Perfect Vacuum | A Perfect Vacuum | Stanislaw Lem | Fictional Author |
| Gian Carlo Spallanzani — Idiota | Idiota | Stanislaw Lem | Fictional author |
| Giancarlo — The Sparrow | The Sparrow | Mary Doria Russell | Local boy at the Naples retreat house |
| Gibarian — Solaris | Solaris | Stanislaw Lem | Deceased Scientist / Dream Apparition |
| Gibbons — The Windup Girl | The Windup Girl | Paolo Bacigalupi | Rogue generipper scientist |
| Gibraltar Chagatai(Chagatai) — Too Like the Lightning | Too Like the Lightning | Ada Palmer | Housekeeper for J.E.D.D. Mason |
| Gideon — Stand on Zanzibar | Stand on Zanzibar | John Brunner | American figure in Beninia |
| Giese — Solaris | Solaris | Stanislaw Lem | Historical Scientist |
| Gilbert Senn(Gil, Gil Senn, Anne) — Adulthood Rites | Adulthood Rites | Octavia E. Butler | Salvager |
| Gilchrist — Doomsday Book | Doomsday Book | Connie Willis | Acting Head of Mediaeval; antagonist-adjacent |
| Gillian Baskin(Dr. Baskin, Gillian, Jill +2) — Startide Rising | Startide Rising | David Brin | Ship's physician and intelligence operative / narrator |
| Gimar — The Dispossessed | The Dispossessed | Ursula K. Le Guin | Anarresti Workmate |
| Girardieau — Revelation Space | Revelation Space | Alastair Reynolds | Militia leader and captor |
| Giraud Nye(Gerry, Nye, Ser Nye +4) — Cyteen | Cyteen | C. J. Cherryh | Head of Reseune Security; Ari I's senior administrator |
| Girl (guider-through) — Use of Weapons | Use of Weapons | Iain M. Banks | Tribal guide/companion |
| Gitta — Chasm City | Chasm City | Alastair Reynolds | Woman from Tanner's past |
| Glimfrelle('Frelle) — A Fire Upon the Deep | A Fire Upon the Deep | Vernor Vinge | minor/crew |
| Glorfindel — Among Others | Among Others | Jo Walton | fairy guide / absent helper |
| Gloriana — The Approach to Al-Mu'tasim | The Approach to Al-Mu'tasim | Jorge Luis Borges | Fictional Queen |
| Glossu Rabban(Rabban, sobrino, Count Glossu Rabban) — Dune | Dune | Frank Herbert | Harkonnen governor of Arrakis |
| Gnostotron(Ontologue Computer, H.P.L.D. model) — The Cyberiad | The Cyberiad | Stanislaw Lem | Digital device / Simulator |
| God-eater(Richard, Paradise) — Virtual Light | Virtual Light | William Gibson | Hacker |
| Goebbels(Dr Goebbels, Reich Minister of Public Enlightenment and Propaganda) — The Separation | The Separation | Christopher Priest | Nazi propaganda minister; documentary film-maker in the alternate history |
| Golan Trevize(Councilman Trevize, Trev, Trevize +1) — Foundation's Edge | Foundation's Edge | Isaac Asimov | Protagonist / Foundation Councilman in exile |
| Goldstein(Enemy of the People, the primal traitor) — 1984 | 1984 | George Orwell | opponent |
| Gomi Boy — Idoru | Idoru | William Gibson | Hardware dealer and hacker |
| Gopal — The Years of Rice and Salt | The Years of Rice and Salt | Kim Stanley Robinson | Supporting |
| Goram(dy Hixar, Captain dy Hixar) — Paladin of Souls | Paladin of Souls | Lois McMaster Bujold | secondary |
| Gordon Bernstein(Gordon, Gaw-dun, Dr. Bernstein +2) — Timescape | Timescape | Gregory Benford | Protagonist (1962–63 thread); experimental physicist |
| Gorodin(Adm. Gorodin, Leonid Gorodin) — Cyteen | Cyteen | C. J. Cherryh | Councillor of Defense; Centrist |
| Goss — The Left Hand of Darkness | The Left Hand of Darkness | Ursula K. Le Guin | helper |
| Gottstein(Commissioner Gottstein, Commissioner) — The Gods Themselves | The Gods Themselves | Isaac Asimov | Earth Commissioner / bureaucratic authority |
| Governor Giarod(System Governor) — Ancillary Sword | Ancillary Sword | Ann Leckie | System governor of Athoek |
| Grace(Assistant Director) — Authority | Authority | Jeff VanderMeer | Assistant Director of the Southern Reach |
| Grace Stevenson(Grace) — Acceptance | Acceptance | Jeff VanderMeer | Assistant Director of the Southern Reach / Survivor |
| Graff(Minister) — Ender's Game | Ender's Game | Orson Scott Card | MinCol Minister / former Battle School commandant |
| Grampar — Among Others | Among Others | Jo Walton | supporting |
| Gran — The Snow Queen | The Snow Queen | Joan D. Vinge | minor/family |
| Grand Examiner — The Uplift War | The Uplift War | David Brin | authority figure/arbitrator |
| Grand Marshal of Codes — The Cyberiad | The Cyberiad | Stanislaw Lem | Official |
| Grand Prince Bullion — The First Sally or The Trap of Gargantius | The First Sally or The Trap of Gargantius | Stanislaw Lem | Noble |
| Grandfather — Ancillary Sword | Ancillary Sword | Ann Leckie | Elder of Valskaayan community |
| Grandmother — The First Sally or The Trap of Gargantius | The First Sally or The Trap of Gargantius | Stanislaw Lem | Local chief of police |
| Grandpa Quartermain(Grandpa) — The Martian Chronicles | The Martian Chronicles | Ray Bradbury | minor |
| Grant(Grant ALX, Grant ALX Warrick, GALX) — Cyteen | Cyteen | C. J. Cherryh | Justin's azi companion, experimental geneset |
| Graubard — The Forever War | The Forever War | Joe Haldeman | Opponent/insubordinate soldier |
| Gravious — Excession | Excession | Iain M. Banks | Simulated creature |
| Great Chancellor(Keeper of the Royal Seal) — The Second Sally or The Offer of King Krool | The Second Sally or The Offer of King Krool | Stanislaw Lem | Court Official |
| Greco — Stories of Your Life and Others | Stories of Your Life and Others | Ted Chiang | Narrator |
| Green Star Doctor — A Canticle for Leibowitz | A Canticle for Leibowitz | Walter M. Miller, Jr. | opponent |
| Greenstalk — A Fire Upon the Deep | A Fire Upon the Deep | Vernor Vinge | actantial:helper |
| Greg(Greg Mansell (per outline), Greg Mansell) — Among Others | Among Others | Jo Walton | helper |
| Greg(Calvin, Commander of Armed Forces) — The Moon Is a Harsh Mistress | The Moon Is a Harsh Mistress | Robert A. Heinlein | Davis family member and drillman |
| Grego — Speaker for the Dead | Speaker for the Dead | Orson Scott Card | Supporting character |
| Gregor(Greg) — Echopraxia | Echopraxia | Peter Watts | Researcher |
| Gregor(the Emperor, Emperor, Emperor Gregor) — Mirror Dance | Mirror Dance | Lois McMaster Bujold | actantial:sender |
| Gregorovius — The Sect of the Phoenix | The Sect of the Phoenix | Jorge Luis Borges | Observer (cited approvingly) |
| Gregory Powell(Powell, Greg, boss) — I, Robot | I, Robot | Isaac Asimov | actantial:subject |
| Greydawn Latesetting X(Greydawn, Captain) — Excession | Excession | Iain M. Banks | Affronter Captain of the Farsight tribe |
| Grondr(Grondr 'Kalir, Grondr Vrinimikalir) — A Fire Upon the Deep | A Fire Upon the Deep | Vernor Vinge | actantial sender |
| Gruda Aplam(Old drone) — Excession | Excession | Iain M. Banks | Contact veteran |
| Grum(old rawhide-skin) — Dreamsnake | Dreamsnake | Vonda N. McIntyre | minor helper |
| Gryphius(Ginzberg, Ginsburg) — Death and the Compass | Death and the Compass | Jorge Luis Borges | Fictitious victim / Alias |
| Gryphius(Ginzberg, Ginsburg, Gryphius-Ginsburg) — The Form of the Sword | The Form of the Sword | Jorge Luis Borges | Informer / Tenant |
| GSV Honest Mistake — Excession | Excession | Iain M. Banks | Ship Mind |
| Gugwei — American Gods | American Gods | Neil Gaiman | secondary character |
| Günberk Braun — Rainbows End | Rainbows End | Vernor Vinge | Alliance cell member |
| Gundhalinu(BZ, Sergeant, Blue +1) — The Snow Queen | The Snow Queen | Joan D. Vinge | Hegemonic Police inspector / POV character |
| Gunnar Erfjord — Ficciones (Tlön, Uqbar, Orbis Tertius) | Ficciones (Tlön, Uqbar, Orbis Tertius) | Jorge Luis Borges | Author of a manuscript |
| Guy Gibson(Flight Lieutenant Guy Gibson, DFC) — The Separation | The Separation | Christopher Priest | RAF night-fighter pilot; later politician |
| Gvarab — The Dispossessed | The Dispossessed | Ursula K. Le Guin | Physics lecturer |
| Gwydion — American Gods | American Gods | Neil Gaiman | minor deity |
| H. X. Borazjani — Red Mars | Red Mars | Kim Stanley Robinson | minor / scientist |
| Hackworth(Gwendolyn Hackworth, John Percival Hackworth, the Alchemist) — The Diamond Age | The Diamond Age | Neal Stephenson | engineer/Drummer boundary-crosser |
| Hagg — The Windup Girl | The Windup Girl | Paolo Bacigalupi | Grahamite priest |
| Hakim(The Veiled) — Tlön, Uqbar, Orbis Tertius | Tlön, Uqbar, Orbis Tertius | Jorge Luis Borges | Heretic/Prophet |
| Hakkuka-jo — Startide Rising | Startide Rising | David Brin | Stenos crew dolphin |
| Halleck(Gurney Halleck) — Dune | Dune | Frank Herbert | returning ally / weapons master |
| Halley(Ráðsviðr) — Perhaps the Stars | Perhaps the Stars | Ada Palmer | Rescuer |
| Halliday — The Forever War | The Forever War | Joe Haldeman | soldier |
| Halrloprillalar(Prill) — Ringworld | Ringworld | Larry Niven | absent helper |
| Ham Tayeh — Gateway | Gateway | Frederik Pohl | crewmate |
| Hamilcar Waterford — Stand on Zanzibar | Stand on Zanzibar | John Brunner | GT treasurer |
| Han Tzu(Hot Soup) — Ender's Game | Ender's Game | Orson Scott Card | Covert ally inside Chinese command |
| Hana(Hana-chan, Hana Ishikawa) — The Coral Bones | The Coral Bones | Jynne Martin | Primary narrator |
| Hanavada — Red Mars | Red Mars | Kim Stanley Robinson | actantial:receiver |
| Hanea — The Years of Rice and Salt | The Years of Rice and Salt | Kim Stanley Robinson | Hodenosaunee diplomat |
| Hannah — Never Let Me Go | Never Let Me Go | Kazuo Ishiguro | Hailsham student |
| Hannah Danner(Danner, Acting Commander, Acting Commander Danner) — Ammonite | Ammonite | Nicola Griffith | Secondary protagonist / institutional authority |
| Hannah Soo(Hannah) — Take Back Plenty | Take Back Plenty | Colin Greenland | Contraband's manager |
| Hannibal Sloat(Mr. Sloat) — Do Androids Dream of Electric Sheep? | Do Androids Dream of Electric Sheep? | Philip K. Dick | supporting |
| Hans Lassen Martensen — Three Versions of Judas | Three Versions of Judas | Jorge Luis Borges | Theologian |
| Hans Mehrer(Cardinal Richelieu) — Gruppenfuhrer Louis XVI | Gruppenfuhrer Louis XVI | Stanislaw Lem | Taudlitz's confidant |
| Hans Schaeffert(Archbishop of Paris) — Gruppenfuhrer Louis XVI | Gruppenfuhrer Louis XVI | Stanislaw Lem | Court Cardinal / Projectionist |
| Hans Wehrholz(Marquis de Beaujolais) — A Perfect Vacuum | A Perfect Vacuum | Stanislaw Lem | Courtier |
| Hans Wehrholz(Marquis de Beaujolais) — Gruppenfuhrer Louis XVI | Gruppenfuhrer Louis XVI | Stanislaw Lem | Courtier |
| Hans Zokker — Odysseus of Ithaca | Odysseus of Ithaca | Stanislaw Lem | Corrupt Explorer |
| Haoke — Startide Rising | Startide Rising | David Brin | Neo-dolphin guard (Tursiops) |
| Harah — Dune | Dune | Frank Herbert | household member |
| Harborizian Cybr — The Third Sally or The Dragons of Probability | The Third Sally or The Dragons of Probability | Stanislaw Lem | Colleague of Trurl |
| Hardy(Private Hardy) — Blackout/All Clear | Blackout/All Clear | Connie Willis | helper |
| Hari Seldon(Wanda Seldon Palver, Raven, Professor Seldon +1) — The Foundation Trilogy | The Foundation Trilogy | Isaac Asimov | mentalic leader / Second Foundation organizer |
| Harkabeeparolyn — Ringworld | Ringworld | Larry Niven | helper |
| Harkad Gosz — The City & The City | The City & The City | China Miéville | Barrister for the True Citizens of Besźel |
| Harla Branno(Mayor Branno, the Mayor, Mayor +3) — Foundation's Edge | Foundation's Edge | Isaac Asimov | Mayor of Terminus / antagonist-driver |
| Harold Willoughby(Willoughby) — Seventy-Two Letters | Seventy-Two Letters | Ted Chiang | Master Sculptor First-Degree |
| Harriet — Among Others | Among Others | Jo Walton | book club member |
| Harroway — I, Robot | I, Robot | Isaac Asimov | Court official employed by Quinn |
| Harry — Never Let Me Go | Never Let Me Go | Kazuo Ishiguro | Hailsham student |
| Harv — The Diamond Age | The Diamond Age | Neal Stephenson | Nell's brother |
| Harwood(Harwood Levine, Cody Harwood) — All Tomorrow's Parties | All Tomorrow's Parties | William Gibson | Billionaire antagonist |
| Hasan(the one-eyed man, eyepatch) — The Years of Rice and Salt | The Years of Rice and Salt | Kim Stanley Robinson | Friend, salon figure |
| Hassan — Starship Troopers | Starship Troopers | Robert A. Heinlein | minor |
| Hassan(Hassan al-Hubbaul) — The Merchant and the Alchemist's Gate | The Merchant and the Alchemist's Gate | Ted Chiang | The Fortunate Rope-Maker |
| Hassop — The Demolished Man | The Demolished Man | Alfred Bester | Minor subordinate |
| Hastings — Blue Mars | Blue Mars | Kim Stanley Robinson | UNTA security commander |
| Hastings — Red Mars | Red Mars | Kim Stanley Robinson | Head of Transitional Authority |
| Haughty widow — Tlön, Uqbar, Orbis Tertius | Tlön, Uqbar, Orbis Tertius | Jorge Luis Borges | Pirate Leader |
| Hayden(Hayden Gordon) — Fledgling | Fledgling | Octavia E. Butler | Elderfather of the Gordon family |
| Hazel — The Moon Is a Harsh Mistress | The Moon Is a Harsh Mistress | Robert A. Heinlein | junior lieutenant |
| Head Fed — Snow Crash | Snow Crash | Neal Stephenson | opponent |
| Head Priest(Divine) — Ancillary Justice | Ancillary Justice | Ann Leckie | interlocutor/witness |
| Headmaster Faust(Madame, Faust) — The Will to Battle | The Will to Battle | Ada Palmer | Jehovah's uncle and Brillist scholar |
| Heather — Lost Futures | Lost Futures | Lisa Tuttle | secondary |
| Heather — Timescape | Timescape | Gregory Benford | Minor helper; Marjorie's friend |
| Heavy Messing — Excession | Excession | Iain M. Banks | Affronter Ship Mind |
| Hegel — Die Kultur als Fehler | Die Kultur als Fehler | Stanislaw Lem | Historical Philosopher |
| Heidi — Take Back Plenty | Take Back Plenty | Colin Greenland | minor/contact |
| Heidi Hyde(Heidi) — Spook Country | Spook Country | William Gibson | Former drummer for the Curfew |
| Helen(Mom) — Blindsight | Blindsight | Peter Watts | Siri's Mother |
| Helen(Huilang Liu) — The Calculating Stars | The Calculating Stars | Mary Robinette Kowal | supporting |
| Helenda — Hyperion | Hyperion | Dan Simmons | Silenus's ex-wife |
| Helmut Bronski — Blue Mars | Blue Mars | Kim Stanley Robinson | UNOMA chief |
| Helmut Bronski — Red Mars | Red Mars | Kim Stanley Robinson | UNOMA chief |
| Heloise — Perhaps the Stars | Perhaps the Stars | Ada Palmer | Traveler in transit |
| Heloïse — Perhaps the Stars | Perhaps the Stars | Ada Palmer | Coordinator/Communicator |
| Heloïse(Sister Heloïse) — The Will to Battle | The Will to Battle | Ada Palmer | Cousin representative in Odessa |
| Heloïse(Sister Heloïse) — Too Like the Lightning | Too Like the Lightning | Ada Palmer | Club participant |
| Henry — Acceptance | Acceptance | Jeff VanderMeer | Leader of the Séance & Science Brigade |
| Henry — The Diamond Age | The Diamond Age | Neal Stephenson | Madame Ping's functionary |
| Herbert Ashe(Ashe) — Ficciones (Tlön, Uqbar, Orbis Tertius) | Ficciones (Tlön, Uqbar, Orbis Tertius) | Jorge Luis Borges | Railway engineer |
| Herbert Ashe — The Form of the Sword | The Form of the Sword | Jorge Luis Borges | Railway engineer |
| Herbert Ashe — Tlön, Uqbar, Orbis Tertius | Tlön, Uqbar, Orbis Tertius | Jorge Luis Borges | Demiurge |
| Herbert Quain — An Examination of the Work of Herbert Quain | An Examination of the Work of Herbert Quain | Jorge Luis Borges | Deceased author |
| Herbert Quain(Quain) — The Circular Ruins | The Circular Ruins | Jorge Luis Borges | Author |
| Herbert Quain — The Form of the Sword | The Form of the Sword | Jorge Luis Borges | Author |
| Herbert Quain(Quain) — Tlön, Uqbar, Orbis Tertius | Tlön, Uqbar, Orbis Tertius | Jorge Luis Borges | Author |
| Herbert Quaine — A Perfect Vacuum (self-review) | A Perfect Vacuum (self-review) | Stanislaw Lem | Fictional author |
| Herbie(RB-34) — I, Robot | I, Robot | Isaac Asimov | Mind-reading robot |
| Hermann Sörgel — Tlön, Uqbar, Orbis Tertius | Tlön, Uqbar, Orbis Tertius | Jorge Luis Borges | Professor Emeritus / Narrator |
| Hermian Ambassador(the Hermian Ambassador) — Rendezvous with Rama | Rendezvous with Rama | Arthur C. Clarke | Political antagonist |
| Hernandez — Virtual Light | Virtual Light | William Gibson | Rydell's former IntenSecure supervisor |
| Herne(Sparks Dawntreader, Starbuck (future role), Starbuck +2) — The Snow Queen | The Snow Queen | Joan D. Vinge | Protagonist-secondary / Queen's consort |
| Herodotus — The Sect of the Phoenix | The Sect of the Phoenix | Jorge Luis Borges | Ancient historian (cited and implicitly criticized) |
| Heron — All Tomorrow's Parties | All Tomorrow's Parties | William Gibson | Former messenger |
| Hershel — The Calculating Stars | The Calculating Stars | Mary Robinette Kowal | supporting |
| Hertz Shemets(Uncle Hertz, Johnny Bear, John) — The Yiddish Policemen's Union | The Yiddish Policemen's Union | Michael Chabon | Antagonist-helper / father figure |
| Hester(Jasper Allen Hester) — Redshirts | Redshirts | John Scalzi | Ensign / Swap survivor |
| Hester Bergowiz — Gateway | Gateway | Frederik Pohl | actantial:helper |
| Het Masteen(True Voice of the Tree, Captain Masteen) — Hyperion | Hyperion | Dan Simmons | Templar Captain (missing) |
| Het Masteen(Masteen, the Templar) — The Fall of Hyperion | The Fall of Hyperion | Dan Simmons | Pilgrim / Templar |
| Hikahi — Startide Rising | Startide Rising | David Brin | Senior neo-dolphin officer / expedition leader |
| Hilali — Blue Mars | Blue Mars | Kim Stanley Robinson | minor |
| Hilali — Red Mars | Red Mars | Kim Stanley Robinson | Vishniac guide |
| Hilary — Dawn | Dawn | Octavia E. Butler | Human survivor |
| Hilary — Lost Futures | Lost Futures | Lisa Tuttle | coworker |
| Hillalum — Stories of Your Life and Others | Stories of Your Life and Others | Ted Chiang | Miner |
| Hillalum — Tower of Babylon | Tower of Babylon | Ted Chiang | Elamite miner |
| Hilleboe(Lieutenant Hilleboe) — The Forever War | The Forever War | Joe Haldeman | Executive officer |
| Hilt — Ammonite | Ammonite | Nicola Griffith | other |
| Hilton Swift(Swift) — Mona Lisa Overdrive | Mona Lisa Overdrive | William Gibson | Sense/Net executive |
| Hinkston — The Martian Chronicles | The Martian Chronicles | Ray Bradbury | Crew, Third Expedition |
| Hinzelmann — American Gods | American Gods | Neil Gaiman | supporting/antagonist-latent |
| Hiro Protagonist(The Deliverator, Hirohito Protagonist, Hiro) — Snow Crash | Snow Crash | Neal Stephenson | protagonist |
| Hiroko — Blue Mars | Blue Mars | Kim Stanley Robinson | Actantial opponent / spiritual leader |
| Hiroko — Green Mars | Green Mars | Kim Stanley Robinson | communal mother / spiritual leader |
| Hiroko(Roko) — Red Mars | Red Mars | Kim Stanley Robinson | Mysterious figure, associated with underground |
| Hiromi — Idoru | Idoru | William Gibson | Official of Tokyo Lo/Rez chapter |
| Hive Queen — Speaker for the Dead | Speaker for the Dead | Orson Scott Card | Helper/actantial object |
| Hjarka — The Stone Sky | The Stone Sky | N. K. Jemisin | Companion / Strongback |
| Hlavin Kitheri(the Reshtar, Reshtar of Galatna, the Reshtar of Galatna Palace) — The Sparrow | The Sparrow | Mary Doria Russell | Jana'ata ruler, perpetrator |
| Hoa(The boy) — The Fifth Season | The Fifth Season | N.K. Jemisin | Companion to the protagonist |
| Hobbs(Baranov) — Pattern Recognition | Pattern Recognition | William Gibson | Former intelligence/SIGINT, Information broker |
| Hock Seng(Yellow Card Boss, Tan Xiansheng, Tan Hock Seng) — The Windup Girl | The Windup Girl | Paolo Bacigalupi | Anderson's yellow card factory manager |
| Holle — Ammonite | Ammonite | Nicola Griffith | Headwoman of Singing Pastures |
| Hollis Henry(Hollis, Ollis) — Spook Country | Spook Country | William Gibson | Journalist and former singer |
| Homer — The Approach to Al-Mu'tasim | The Approach to Al-Mu'tasim | Jorge Luis Borges | Ancient Poet |
| Homer(Flaminius Rufus, Cartaphilus, Nobody) — The Circular Ruins | The Circular Ruins | Jorge Luis Borges | Immortal / Wanderer |
| Homer M. Odysseus(Odysseus) — A Perfect Vacuum | A Perfect Vacuum | Stanislaw Lem | Fictional Protagonist / Coordinator |
| Homer Maria Odysseus(Homer M. Odysseus, Odysseus of Ithaca) — Odysseus of Ithaca | Odysseus of Ithaca | Stanislaw Lem | Protagonist |
| Homo optimisans se ipse(Autocreator, Self-Maker) — Die Kultur als Fehler | Die Kultur als Fehler | Stanislaw Lem | Future human ideal |
| Horza(Bora Horza Gobuchul) — Ancillary Sword | Ancillary Sword | Ann Leckie | protagonist / Changer |
| Hossner — Story of Your Life | Story of Your Life | Ted Chiang | Government Official |
| Hotaka Andō Mitsubishi(Andō, Chief Executive Director, Chief Director +3) — Seven Surrenders | Seven Surrenders | Ada Palmer | Chief Director of the Mitsubishi Hive |
| Hotaka Andō Mitsubishi(Chief Director, Andō, Chief Director Andō +3) — Too Like the Lightning | Too Like the Lightning | Ada Palmer | Mitsubishi Hive Leader |
| Houwha(Hoa) — The Stone Sky | The Stone Sky | N. K. Jemisin | Narrator / stone eater / Essun's companion |
| Hrabanus Maurus — The Sect of the Phoenix | The Sect of the Phoenix | Jorge Luis Borges | Medieval scholar (cited source) |
| Hsi P'eng — The Garden of Forking Paths | The Garden of Forking Paths | Jorge Luis Borges | Consul |
| Hu Die — The Years of Rice and Salt | The Years of Rice and Salt | Kim Stanley Robinson | other |
| Huang Enlai — Perhaps the Stars | Perhaps the Stars | Ada Palmer | Director of Fuxing |
| Hubertus Bigend(Bernard, Hubertus, Bigend) — Pattern Recognition | Pattern Recognition | William Gibson | Founder of Blue Ant |
| Hubertus Bigend(Bigend, Hubertus) — Spook Country | Spook Country | William Gibson | Wealthy backer and investigator |
| Huellis — Ammonite | Ammonite | Nicola Griffith | other |
| Hugh — Among Others | Among Others | Jo Walton | emerging karass member |
| Hugh Tang(Hugh) — Fledgling | Fledgling | Octavia E. Butler | Stefan's symbiont |
| Hughes — Starship Troopers | Starship Troopers | Robert A. Heinlein | minor |
| Hugo — Imago | Imago | Octavia E. Butler | Guard |
| Hullcare Amnion(Spokesman Hullcare Amnion) — The Fall of Hyperion | The Fall of Hyperion | Dan Simmons | Ouster Tribunal member |
| Human — Speaker for the Dead | Speaker for the Dead | Orson Scott Card | Piggy leader / covenant-maker |
| Humphries — The Evolution of Human Science | The Evolution of Human Science | Ted Chiang | Researcher |
| Hundred Captain Rubran — Ancillary Justice | Ancillary Justice | Ann Leckie | Ship officer |
| Hussinger — Timescape | Timescape | Gregory Benford | minor |
| Huxley(Huxley Mojave) — Perhaps the Stars | Perhaps the Stars | Ada Palmer | Utopian guardian and First Contact Constellation member |
| I-Chen — The Years of Rice and Salt | The Years of Rice and Salt | Kim Stanley Robinson | Ship's doctor, linguist, scientist |
| I-Li — The Years of Rice and Salt | The Years of Rice and Salt | Kim Stanley Robinson | supporting |
| Iagogeh(the One Who Hears) — The Years of Rice and Salt | The Years of Rice and Salt | Kim Stanley Robinson | helper/strategist |
| Ibn Ezra — The Years of Rice and Salt | The Years of Rice and Salt | Kim Stanley Robinson | Helper / interlocutor |
| Ibrahim(Dr. Ibrahim) — The Years of Rice and Salt | The Years of Rice and Salt | Kim Stanley Robinson | Husband, historian, imperial memorialist |
| Ida — The Calculating Stars | The Calculating Stars | Mary Robinette Kowal | helper |
| Idas — Nova | Nova | Samuel R. Delany | Cyborg stud |
| Idelba(Aunt Idelba) — The Years of Rice and Salt | The Years of Rice and Salt | Kim Stanley Robinson | scientist/soul-cluster member |
| Idiarte Borda — Tlön, Uqbar, Orbis Tertius | Tlön, Uqbar, Orbis Tertius | Jorge Luis Borges | President/Victim |
| IF(Illegal Facilitator) — Spook Country | Spook Country | William Gibson | Target of surveillance |
| Igor — The Coral Bones | The Coral Bones | Jynne Martin | Veteran Committee spotter |
| Ilia Volyova(Volyova, Ilia) — Revelation Space | Revelation Space | Alastair Reynolds | Triumvir and weapons expert |
| Illvin(Lord Illvin, Lord Illvin dy Arbanos, Ser dy Arbanos) — Paladin of Souls | Paladin of Souls | Lois McMaster Bujold | helper/love-interest |
| Illyan(Commander Illyan, Simon Illyan, Simon +1) — Barrayar | Barrayar | Lois McMaster Bujold | actantial helper |
| Immortal Narrator — Tlön, Uqbar, Orbis Tertius | Tlön, Uqbar, Orbis Tertius | Jorge Luis Borges | Lookout / Informant |
| Ina — Stories of Your Life and Others | Stories of Your Life and Others | Ted Chiang | Tamera's roommate |
| Inchmale(Reg, Willy) — Spook Country | Spook Country | William Gibson | Music Producer/Former Bandmate |
| Indah(Senior Officer Indah) — Network Effect | Network Effect | Martha Wells | Preservation Station Security senior officer |
| Inez — Imago | Imago | Octavia E. Butler | Human old fertile |
| Ingram — Forever Peace | Forever Peace | Joe Haldeman | prisoner/resource |
| Innon(Innon Resistant Meov) — The Fifth Season | The Fifth Season | N.K. Jemisin | Pirate captain and Meov leader |
| Inspector Bryant(Harry Bryant) — Do Androids Dream of Electric Sheep? | Do Androids Dream of Electric Sheep? | Philip K. Dick | actantial:sender |
| Iosif — Fledgling | Fledgling | Octavia E. Butler | Shori's Ina father |
| Irene Pepperberg — The Great Silence | The Great Silence | Ted Chiang | Human researcher |
| Ireneo Funes(chronometric Funes) — Funes the Memorious | Funes the Memorious | Jorge Luis Borges | Protagonist/Subject |
| Ireneo Funes — Tlön, Uqbar, Orbis Tertius | Tlön, Uqbar, Orbis Tertius | Jorge Luis Borges | Mnemonist |
| Iriarte — Adulthood Rites | Adulthood Rites | Octavia E. Butler | Raider |
| Iriarte — Imago | Imago | Octavia E. Butler | Human raider |
| Iris — Network Effect | Network Effect | Martha Wells | helper |
| Irongrip — The Uplift War | The Uplift War | David Brin | Antagonist / assigned ceremonial partner |
| Isaac Dan der Grimnebulin(Isaac, Grimnebulin, captain +5) — Perdido Street Station | Perdido Street Station | China Miéville | Scientist and leader of the moth-hunting crew |
| Isaac Edward Leibowitz(the Beatus, the Blessed Leibowitz, I. E. L. +2) — A Canticle for Leibowitz | A Canticle for Leibowitz | Walter M. Miller, Jr. | actantial object |
| Isaac Lakin(Lakin, Isaac) — Timescape | Timescape | Gregory Benford | Opponent; department head at UCSD |
| Isaac Luria — The Approach to Al-Mu'tasim | The Approach to Al-Mu'tasim | Jorge Luis Borges | Kabbalist |
| Isaac Szpindel(Szpindel, Isaac) — Blindsight | Blindsight | Peter Watts | Original Biologist |
| Isabel Carlos II(King of Spain, King Prime Minister) — Seven Surrenders | Seven Surrenders | Ada Palmer | King of Spain |
| Isabelle Nancy(Professor Nancy, Izzy) — The City & The City | The City & The City | China Miéville | Archaeology Professor and Mahalia's advisor |
| Ismail(Dr. Ismail, Ismail ibn Mani al-Dir) — The Years of Rice and Salt | The Years of Rice and Salt | Kim Stanley Robinson | POV character, Ottoman physician |
| Ista(Royina Ista, Sera dy Ajelo, Dowager Royina +4) — Paladin of Souls | Paladin of Souls | Lois McMaster Bujold | protagonist |
| Ivan Vorpatril(Lieutenant Lord Vorpatril) — Mirror Dance | Mirror Dance | Lois McMaster Bujold | helper/opponent |
| Ivana — Green Mars | Green Mars | Kim Stanley Robinson | Red founder |
| Ivy — Pattern Recognition | Pattern Recognition | William Gibson | Online community founder |
| Iwa — The Years of Rice and Salt | The Years of Rice and Salt | Kim Stanley Robinson | helper |
| Iwang — The Years of Rice and Salt | The Years of Rice and Salt | Kim Stanley Robinson | Tibetan glassblower and mathematician |
| J. R. Isidore(John Isidore, special, chickenhead +5) — Do Androids Dream of Electric Sheep? | Do Androids Dream of Electric Sheep? | Philip K. Dick | protagonist (secondary) |
| J.E.D.D. Mason(Jehovah, Ἄναξ, The Addressee +14) — The Will to Battle | The Will to Battle | Ada Palmer | Divine incarnate and global challenger |
| Ja — A Fire Upon the Deep | A Fire Upon the Deep | Vernor Vinge | minor helper |
| Jacira(Jacira Paz-Viveiros) — The Calculating Stars | The Calculating Stars | Mary Robinette Kowal | helper |
| Jack — Lost Futures | Lost Futures | Lisa Tuttle | Clare's father |
| Jack Brennan — Ringworld | Ringworld | Larry Niven | other |
| Jack Half-a-Prayer(Half-a-Prayer) — Perdido Street Station | Perdido Street Station | China Miéville | Fighter |
| Jack Roan(Roan) — Fledgling | Fledgling | Octavia E. Butler | Katharine's symbiont |
| Jackie(Jackie Boone) — Blue Mars | Blue Mars | Kim Stanley Robinson | Second-generation Martian / political actor |
| Jackie(Project girl, angel) — Count Zero | Count Zero | William Gibson | Associate of Two-a-Day / Rescuer |
| Jackie — Green Mars | Green Mars | Kim Stanley Robinson | Native Martian political leader; Marsfirst figurehead |
| Jackie(Jackie Boone) — Red Mars | Red Mars | Kim Stanley Robinson | Second-generation Martian / political actor |
| Jackie Severance — Acceptance | Acceptance | Jeff VanderMeer | Emissary of Central |
| Jackson Beck(Jax) — The Demolished Man | The Demolished Man | Alfred Bester | Helper to Powell |
| Jacquel — American Gods | American Gods | Neil Gaiman | helper/old god |
| Jaidee(Tiger of Bangkok, Khun Jaidee, Captain Jaidee) — The Windup Girl | The Windup Girl | Paolo Bacigalupi | Environment Ministry captain; idealist enforcer |
| James Alexander Nolan(Nolan) — The Circular Ruins | The Circular Ruins | Jorge Luis Borges | Playwright and conspirator |
| James Alexander Nolan(Nolan) — The Form of the Sword | The Form of the Sword | Jorge Luis Borges | Conspirator and playwright |
| James Alexander Nolan(James Nolan) — Theme of the Traitor and the Hero | Theme of the Traitor and the Hero | Jorge Luis Borges | Oldest comrade / Choreographer |
| James Delmore Shapely(J.D. Shapely, Shapely) — Virtual Light | Virtual Light | William Gibson | Historical figure / HIV survivor |
| James Joyce — Gigamesh | Gigamesh | Stanislaw Lem | Literary Predecessor |
| James Joyce — The Approach to Al-Mu'tasim | The Approach to Al-Mu'tasim | Jorge Luis Borges | Author |
| James Nolan — Tlön, Uqbar, Orbis Tertius | Tlön, Uqbar, Orbis Tertius | Jorge Luis Borges | Investigator / Playwright |
| Jamis — Dune | Dune | Frank Herbert | actantial:opponent |
| Jan(Jan Rodricks, the last man) — Childhood's End | Childhood's End | Arthur C. Clarke | protagonist (stowaway arc) |
| Jan(Jannaveg, Jan the sailmaker) — Lord of Light | Lord of Light | Roger Zelazny | Informant / Old acquaintance |
| Jan Trenglets — A Fire Upon the Deep | A Fire Upon the Deep | Vernor Vinge | opponent |
| Jane(Jane 23, Jane, Age 19) — A Closed and Common Orbit | A Closed and Common Orbit | Becky Chambers | protagonist |
| Jane — Speaker for the Dead | Speaker for the Dead | Orson Scott Card | AI inhabiting ansible network, Ender's companion |
| Jane 64(64) — A Closed and Common Orbit | A Closed and Common Orbit | Becky Chambers | opponent |
| Jane Strassen(Maddy Morley-Strassen, Maddy, Janie +3) — Cyteen | Cyteen | C. J. Cherryh | Wing One lab administrator and Ari II's surrogate mother-figure |
| Janet Eagan(Eagan) — Ammonite | Ammonite | Nicola Griffith | Absent helper / opponent by withdrawal |
| Janice — The Peripheral | The Peripheral | William Gibson | Friend / Caretaker |
| Janice Reilly — Hell Is the Absence of God | Hell Is the Absence of God | Ted Chiang | Inspirational speaker and Pilgrim |
| Janice Reilly(Janice) — Stories of Your Life and Others | Stories of Your Life and Others | Ted Chiang | Evangelist / Light-seeker |
| Janine — Among Others | Among Others | Jo Walton | emerging karass member |
| Janine(Ofwarren) — The Handmaid's Tale | The Handmaid's Tale | Margaret Atwood | Handmaid in labor |
| Janitor — Authority | Authority | Jeff VanderMeer | Cleaning Staff |
| Janos Bartok(Safety Officer Bartok) — The Fountains of Paradise | The Fountains of Paradise | Arthur C. Clarke | actantial:opponent |
| Janov Pelorat(Professor Pelorat, Pel, Pelorat +1) — Foundation's Edge | Foundation's Edge | Isaac Asimov | Mythologist and historian |
| Japanese businessman(neo-traditional, neotraditional) — Snow Crash | Snow Crash | Neal Stephenson | opponent |
| Japril — Stars in My Pocket Like Grains of Sand | Stars in My Pocket Like Grains of Sand | Samuel R. Delany | Official / Informant |
| Jaromir Hladik(Hladik) — The Form of the Sword | The Form of the Sword | Jorge Luis Borges | Playwright / Condemned Prisoner |
| Jaromir Hladik — The Secret Miracle | The Secret Miracle | Jorge Luis Borges | Protagonist and author |
| Jaromir Hladik — Three Versions of Judas | Three Versions of Judas | Jorge Luis Borges | Author |
| Jaromir Hladik — Tlön, Uqbar, Orbis Tertius | Tlön, Uqbar, Orbis Tertius | Jorge Luis Borges | Author / Prisoner |
| Jaroslav Kubin — The Secret Miracle | The Secret Miracle | Jorge Luis Borges | Character in play |
| Jason — Snow Crash | Snow Crash | Neal Stephenson | minor |
| Jasper — The Fifth Season | The Fifth Season | N.K. Jemisin | Grit |
| Javier — Imago | Imago | Octavia E. Butler | Human mate to Aaor |
| Jax — Exhalation | Exhalation | Ted Chiang | Neuroblast digient |
| Jax — The Lifecycle of Software Objects | The Lifecycle of Software Objects | Ted Chiang | Neuroblast digient |
| Jdahya(Kaaltediinjdahya lel Kahguyaht aj Dinso) — Dawn | Dawn | Octavia E. Butler | Oankali Teacher/Guide |
| Jdahya(Creature, Kaaljdahyatediin lel Kahguyaht aj Dinso) — Imago | Imago | Octavia E. Butler | Oankali male |
| Jean — Childhood's End | Childhood's End | Arthur C. Clarke | Party guest, George's companion |
| Jean — Dreamsnake | Dreamsnake | Vonda N. McIntyre | Minor helper |
| Jean Pelerin — Dawn | Dawn | Octavia E. Butler | Human survivor |
| Jeff — Childhood's End | Childhood's End | Arthur C. Clarke | Transcending child |
| Jeff Winthrop — Liking What You See: A Documentary | Liking What You See: A Documentary | Ted Chiang | Anti-calli campaign participant |
| Jeff Winthrop — Stories of Your Life and Others | Stories of Your Life and Others | Ted Chiang | 3rd-year student |
| Jeff Young — Stand on Zanzibar | Stand on Zanzibar | John Brunner | Vignette figure / saboteur |
| Jeffers — The Peripheral | The Peripheral | William Gibson | State Police officer |
| Jefferson(Colonel Zamat Jefferson, Dr. Jefferson) — Forever Peace | Forever Peace | Joe Haldeman | helper/ambiguous |
| Jefri(Jefri Olsndot, Amdijefri) — A Fire Upon the Deep | A Fire Upon the Deep | Vernor Vinge | protagonist (planetary strand) |
| Jehovah(T.M., Master, Fili +23) — Perhaps the Stars | Perhaps the Stars | Ada Palmer | God-like entity and focal point of factional conflicts |
| Jen Shinnan — Ancillary Justice | Ancillary Justice | Ann Leckie | Upper-city conspirator / opponent |
| Jen Taa — Ancillary Justice | Ancillary Justice | Ann Leckie | minor character |
| Jenkins — Redshirts | Redshirts | John Scalzi | Theorist / Threshold guardian |
| Jennifer Chase — The Lifecycle of Software Objects | The Lifecycle of Software Objects | Ted Chiang | Representative from Binary Desire |
| Jennifer Mo — All Tomorrow's Parties | All Tomorrow's Parties | William Gibson | Test subject |
| Jeremy Brauer(Brauer) — The Lifecycle of Software Objects | The Lifecycle of Software Objects | Ted Chiang | Representative from Exponential Appliances |
| Jerome K. Jerome(Jay) — To Say Nothing of the Dog | To Say Nothing of the Dog | Connie Willis | Historical figure (cameo) |
| Jerry Church(Church) — The Demolished Man | The Demolished Man | Alfred Bester | Fence/criminal helper |
| Jerry Kirchoff(Jerry, the Exec) — Rendezvous with Rama | Rendezvous with Rama | Arthur C. Clarke | supporting |
| Jerusha PalaThion(Inspector PalaThion, Inspector, Commander +1) — The Snow Queen | The Snow Queen | Joan D. Vinge | POV protagonist / Hegemonic Police Commander |
| Jessamine Chest(Mrs. Jessamine Chest) — A Perfect Vacuum | A Perfect Vacuum | Stanislaw Lem | Eccentric Heiress |
| Jesse — Dreamsnake | Dreamsnake | Vonda N. McIntyre | catalyst / dying companion |
| Jesse's brother — Dreamsnake | Dreamsnake | Vonda N. McIntyre | opponent |
| Jessica — Blue Mars | Blue Mars | Kim Stanley Robinson | Colleague |
| Jessica(Dama Jessica, Lady Jessica, Sayyadina +5) — Dune | Dune | Frank Herbert | Bene Gesserit, mother of Muad'Dib |
| Jessica — Green Mars | Green Mars | Kim Stanley Robinson | Biotique scientist |
| Jessica — Red Mars | Red Mars | Kim Stanley Robinson | colleague / Biotique scientist |
| Jessica Hsyu(Hsyu) — Authority | Authority | Jeff VanderMeer | Southern Reach Staff Member |
| Jessica Oehlsen(Mrs. Oehlsen, Glenn) — Anxiety Is the Dizziness of Freedom | Anxiety Is the Dizziness of Freedom | Ted Chiang | Jessica's Son, Murderer |
| Jesus — American Gods | American Gods | Neil Gaiman | other |
| Jesus Christ(The Word, The Redeemer, Christ +1) — Three Versions of Judas | Three Versions of Judas | Jorge Luis Borges | Biblical Figure |
| Jesusa(Jesusita) — Imago | Imago | Octavia E. Butler | Human mate to Jodahs |
| Jete — Network Effect | Network Effect | Martha Wells | B-E guard / human shield |
| Jiiji (Haru Ishikawa)(Jiiji, Haru Ishikawa) — The Coral Bones | The Coral Bones | Jynne Martin | Hana's grandfather |
| Jija — The Fifth Season | The Fifth Season | N.K. Jemisin | Essun's husband |
| Jija(Jija Resistant Jekity) — The Stone Sky | The Stone Sky | N. K. Jemisin | Antagonist (deceased) |
| Jijingi — Exhalation | Exhalation | Ted Chiang | Scribe / Student |
| Jijingi — The Truth of Fact, the Truth of Feeling | The Truth of Fact, the Truth of Feeling | Ted Chiang | Tiv Scribe |
| Jill Boardman(Nurse Boardman, little one, pretty foots +2) — Stranger in a Strange Land | Stranger in a Strange Land | Robert A. Heinlein | Smith's protector and water-sister |
| Jim(Dad) — Blindsight | Blindsight | Peter Watts | Siri's Father |
| Jim — Cyteen | Cyteen | C. J. Cherryh | security guard |
| Jim — To Say Nothing of the Dog | To Say Nothing of the Dog | Connie Willis | Early Oxford time-travel researcher |
| Jim Holden — Ancillary Sword | Ancillary Sword | Ann Leckie | protagonist / executive officer |
| Jim Moore(Dad) — Blindsight | Blindsight | Peter Watts | Siri's father |
| Jim Moore(Moore, Colonel Carnage, Jim +3) — Echopraxia | Echopraxia | Peter Watts | Military man / Strategist |
| Jimmie Bearpaw(Candidate Bearpaw, Third Lieutenant Bearpaw) — Starship Troopers | Starship Troopers | Robert A. Heinlein | helper/trainee |
| Jimmy — Neuromancer | Neuromancer | William Gibson | Burglar |
| Jimmy Hanson(Hanson) — Redshirts | Redshirts | John Scalzi | Ensign / Narrative function |
| Jimmy Norton — The Separation | The Separation | Christopher Priest | British Olympic rowing coach |
| Jimmy Pak(Lt. Pak, Lt. James Pak, Dragonfly) — Rendezvous with Rama | Rendezvous with Rama | Arthur C. Clarke | junior officer / aviator |
| Jimmy Quinn(Sparky, Jim, Mr. Quinn +4) — The Sparrow | The Sparrow | Mary Doria Russell | Radio astronomer who discovers the alien signal |
| Jin Im-Jin(Speaker, Grandpa, Speaker Jin Im-Jin +2) — The Will to Battle | The Will to Battle | Ada Palmer | Speaker of the Senate |
| Jo ¼maine — The Demolished Man | The Demolished Man | Alfred Bester | Helper to Reich/legal obstacle |
| Jo-Jo — The Uplift War | The Uplift War | David Brin | Helper / atavistic chim |
| Joachim Fersengeld — A Perfect Vacuum | A Perfect Vacuum | Stanislaw Lem | Fictional Author |
| Joachim Fersengeld(prophet, Enemy of Man) — Perycalypsis | Perycalypsis | Stanislaw Lem | Author and self-proclaimed prophet |
| Joan — Lost Futures | Lost Futures | Lisa Tuttle | helper |
| Joan — The Foundation Trilogy | The Foundation Trilogy | Isaac Asimov | helper |
| João — Imago | Imago | Octavia E. Butler | Human captive/patient |
| JoBonnot — Stars in My Pocket Like Grains of Sand | Stars in My Pocket Like Grains of Sand | Samuel R. Delany | Manipulator/Offworlder |
| Jodahs(I, Eka, Oeka +2) — Imago | Imago | Octavia E. Butler | Narrative protagonist and ooloi construct |
| Joe(Chung Joe) — Air | Air | Geoff Ryman | opponent-turned-helper |
| Joe — Childhood's End | Childhood's End | Arthur C. Clarke | Extremist captor/guard |
| Joe Calvert(Lt Calvert, Joe) — Rendezvous with Rama | Rendezvous with Rama | Arthur C. Clarke | Navigating officer |
| Joe Sawyer(JL, J. L. Sawyer, Jack +6) — The Separation | The Separation | Christopher Priest | RAF bomber pilot; Olympic rower; one of identical twin brothers |
| Joel — Fledgling | Fledgling | Octavia E. Butler | Shori's human symbiont |
| Joen(Dowager Princess Joen, Princess Joen, August Mother +1) — Paladin of Souls | Paladin of Souls | Lois McMaster Bujold | antagonist |
| Jogajong — Stand on Zanzibar | Stand on Zanzibar | John Brunner | Revolutionary Leader / Ideological Foil |
| Jogoroth Sobhaddartha — Foundation's Edge | Foundation's Edge | Isaac Asimov | Customs official |
| Johan Rajasinghe(Ambassador Rajasinghe) — The Fountains of Paradise | The Fountains of Paradise | Arthur C. Clarke | confidant / audience surrogate |
| Johann Wieland(Heinz Karl Muller, Duc de Rohan, Monsieur le Due) — Gruppenfuhrer Louis XVI | Gruppenfuhrer Louis XVI | Stanislaw Lem | Taudlitz's emissary and confidant |
| Johanna Olsndot(Jo Haugen) — A Fire Upon the Deep | A Fire Upon the Deep | Vernor Vinge | protagonist (planetary strand) |
| Johannes Dahlmann — The Circular Ruins | The Circular Ruins | Jorge Luis Borges | Minister |
| Johannes Dahlmann — Tlön, Uqbar, Orbis Tertius | Tlön, Uqbar, Orbis Tertius | Jorge Luis Borges | Patient/Traveler |
| Johannes Grisebach(the young man, disciple) — The Form of the Sword | The Form of the Sword | Jorge Luis Borges | Prospective disciple |
| Johannes Valentinus Andrea(Andrea) — Ficciones (Tlön, Uqbar, Orbis Tertius) | Ficciones (Tlön, Uqbar, Orbis Tertius) | Jorge Luis Borges | Theologian and author |
| Johannes Voelker(Voelker) — The Sparrow | The Sparrow | Mary Doria Russell | Jesuit official / antagonist in Rome frame |
| John — I, Robot | I, Robot | Isaac Asimov | Hidden crippled man; Byerley's secret |
| John (Hathaway's son) — The Martian Chronicles | The Martian Chronicles | Ray Bradbury | Robot simulacrum / surrogate son |
| John Boone(Big Man) — Blue Mars | Blue Mars | Kim Stanley Robinson | Charismatic visionary and political figure |
| John Boone(Big Man, John) — Red Mars | Red Mars | Kim Stanley Robinson | First man on Mars, political visionary |
| John Candotti(John) — The Sparrow | The Sparrow | Mary Doria Russell | Young Jesuit priest / Sandoz's advocate |
| John Chapman(Apple Johnny, Johnny Chapman) — American Gods | American Gods | Neil Gaiman | minor ally (declining) |
| John H. Watson — The Approach to Al-Mu'tasim | The Approach to Al-Mu'tasim | Jorge Luis Borges | Fictional Doctor |
| John of the Rood — The Sect of the Phoenix | The Sect of the Phoenix | Jorge Luis Borges | Cult member and liturgical poet |
| John William Quigley(Wilfred Quarles) — An Examination of the Work of Herbert Quain | An Examination of the Work of Herbert Quain | Jorge Luis Borges | Character in 'The Secret Mirror' |
| John William Quigley(Wilfred Quarles) — The Circular Ruins | The Circular Ruins | Jorge Luis Borges | Playwright / Traveling salesman |
| John William Quigley(Wilfred Quarles) — Tlön, Uqbar, Orbis Tertius | Tlön, Uqbar, Orbis Tertius | Jorge Luis Borges | Playwright/Salesman |
| Johnny(John Keats cybrid, Keats cybrid) — Hyperion | Hyperion | Dan Simmons | AI cybrid / protagonist-partner |
| Johnny — Timescape | Timescape | Gregory Benford | Renfrew's young son |
| Jojo Bernal(Jojo) — New York 2140 | New York 2140 | Kim Stanley Robinson | Franklin's date |
| Jonathan — Blackout/All Clear | Blackout/All Clear | Connie Willis | Commander's grandson / crew |
| Jonny(Villa) — The Uplift War | The Uplift War | David Brin | Minor character / gorilla |
| Jorge — Exhalation | Exhalation | Ted Chiang | Support Group Member |
| Jorge Luis Borges(Borges) — A Perfect Vacuum (self-review) | A Perfect Vacuum (self-review) | Stanislaw Lem | Referenced author |
| Jorge Luis Borges(Narrator, Yo) — Ficciones (Tlön, Uqbar, Orbis Tertius) | Ficciones (Tlön, Uqbar, Orbis Tertius) | Jorge Luis Borges | Narrator and investigator |
| Jorge Luis Borges(Borges, J.L.B.) — Tlön, Uqbar, Orbis Tertius | Tlön, Uqbar, Orbis Tertius | Jorge Luis Borges | Narrator/Protagonist |
| Joseph(Joe) — Dawn | Dawn | Octavia E. Butler | Lilith's mate and closest ally |
| Joseph — Imago | Imago | Octavia E. Butler | Human survivor |
| Joseph Cartaphilus — Tlön, Uqbar, Orbis Tertius | Tlön, Uqbar, Orbis Tertius | Jorge Luis Borges | Rare book dealer |
| Joseph Severn(John Keats, Johnny, the persona +11) — The Fall of Hyperion | The Fall of Hyperion | Dan Simmons | First-person narrator; TechnoCore cybrid of Keats serving as observer to Gladstone |
| Joseph Weingartner — Liking What You See: A Documentary | Liking What You See: A Documentary | Ted Chiang | Neurologist |
| Joseph Weingartner — Stories of Your Life and Others | Stories of Your Life and Others | Ted Chiang | Expert |
| Joshua Chen — The Gods Themselves | The Gods Themselves | Isaac Asimov | opponent |
| Joshua Sadbottham(J. Sadbottham) — Die Kultur als Fehler | Die Kultur als Fehler | Stanislaw Lem | Philosopher |
| Josie(animal, Miss Josie) — Klara and the Sun | Klara and the Sun | Kazuo Ishiguro | Klara's owner and Rick's friend |
| Joyce — Green Mars | Green Mars | Kim Stanley Robinson | Praxis scholarship apprentice |
| Joyce(Madame) — The Will to Battle | The Will to Battle | Ada Palmer | Former Blacklaw, newly registered European/Spaniard |
| Joyce Faust(Madame, Headmaster Faust, Headmaster +1) — Seven Surrenders | Seven Surrenders | Ada Palmer | Master of Brill's Institute of Psychotaxonomic Science |
| Ju-mei — Air | Air | Geoff Ryman | Mae's brother |
| Juan Dahlmann(Dahlmann) — The Form of the Sword | The Form of the Sword | Jorge Luis Borges | Protagonist |
| Juan Dahlmann(Dahlmann, Sr. Dahlmann) — The South | The South | Jorge Luis Borges | protagonist |
| Juan Facundo Quiroga — The Form of the Sword | The Form of the Sword | Jorge Luis Borges | Federalist caudillo |
| Juan Jose de Cordoba — Forever Peace | Forever Peace | Joe Haldeman | other |
| Juan Manuel de Rosas — The Form of the Sword | The Form of the Sword | Jorge Luis Borges | Dictator of Argentina |
| Juan Muraña — Tlön, Uqbar, Orbis Tertius | Tlön, Uqbar, Orbis Tertius | Jorge Luis Borges | Knife Fighter |
| Juan Orozco(Juan) — Rainbows End | Rainbows End | Vernor Vinge | actantial:subject |
| Juan Rico(Johnnie, Juan, Mr. Rico +1) — Starship Troopers | Starship Troopers | Robert A. Heinlein | protagonist/narrator |
| Juanita Marquez — Snow Crash | Snow Crash | Neal Stephenson | helper |
| Jubal Harshaw(Jubal, Boss, Doctor Harshaw +4) — Stranger in a Strange Land | Stranger in a Strange Land | Robert A. Heinlein | Protagonist's guardian and strategist |
| Judas Iscariot(Judas) — Three Versions of Judas | Three Versions of Judas | Jorge Luis Borges | Biblical Apostle |
| Judith Pooke(Judith Holliman, Miss Holliman, J.J. Pooke +1) — The Coral Bones | The Coral Bones | Jynne Martin | Naturalist aboard the Kittiwake / historical figure |
| Judy Tsuzuki(Keiko) — Pattern Recognition | Pattern Recognition | William Gibson | Persona model / Barmaid |
| Jukka Sarasti(Sarasti, vampire, bloodsucker +4) — Blindsight | Blindsight | Peter Watts | Commander of the Theseus |
| Jules Chardaman — Timescape | Timescape | Gregory Benford | minor |
| Jules Nefastes — Les Robinsonades | Les Robinsonades | Stanislaw Lem | Critic |
| Julia(the dark-haired girl, the girl with dark hair, the girl) — 1984 | 1984 | George Orwell | antagonist (perceived) |
| Julia — Tlön, Uqbar, Orbis Tertius | Tlön, Uqbar, Orbis Tertius | Jorge Luis Borges | Acquaintance |
| Julia(Conclave Chief) — Too Like the Lightning | Too Like the Lightning | Ada Palmer | Sensayer |
| Julia de Weidenau — The Secret Miracle | The Secret Miracle | Jorge Luis Borges | Character in play |
| Julia Doria-Pamphili(votre sainteté, Doria-Pamphili, Pontifex Maxima +1) — Perhaps the Stars | Perhaps the Stars | Ada Palmer | Conclave leader and assigned tracker |
| Julia Doria-Pamphili(Julia, Pontifex Maxima) — Seven Surrenders | Seven Surrenders | Ada Palmer | Sensayer Network Leader |
| Julia Doria-Pamphili(Conclave Head) — The Will to Battle | The Will to Battle | Ada Palmer | Head of the Sensayers' Conclave |
| Julian(Julian Class, Sergeant Class, the black physicist) — Forever Peace | Forever Peace | Joe Haldeman | Protagonist, mechanic/sergeant, physicist |
| Juliana Burgos — Tlön, Uqbar, Orbis Tertius | Tlön, Uqbar, Orbis Tertius | Jorge Luis Borges | Servant/Mistress |
| Julie — Ancillary Sword | Ancillary Sword | Ann Leckie | captive protagonist |
| Julie Deane(Julie) — Neuromancer | Neuromancer | William Gibson | Information broker / fence |
| Julius Rothe(Capt. Julius Rothe) — The Secret Miracle | The Secret Miracle | Jorge Luis Borges | Gestapo Captain |
| Julius Rothe — Tlön, Uqbar, Orbis Tertius | Tlön, Uqbar, Orbis Tertius | Jorge Luis Borges | Gestapo Captain |
| Justin Warrick(Justin, JW, Dr. Warrick +2) — Cyteen | Cyteen | C. J. Cherryh | Special psychdesigner at Reseune; internal dissident; Corain contact |
| K-K-Kph-kree(Nukapai) — Startide Rising | Startide Rising | David Brin | Cetacean mythological god / deep entity |
| K'tha-Jon — Startide Rising | Startide Rising | David Brin | Stenos bosun / secret experimental subject |
| Kaede — Network Effect | Network Effect | Martha Wells | helper |
| Kahguyaht — Adulthood Rites | Adulthood Rites | Octavia E. Butler | Ooloi parent |
| Kahguyaht — Dawn | Dawn | Octavia E. Butler | Oankali ooloi parent |
| Kahguyaht(Ahtrekahguyahtkaal lel Jdayhatediin aj Dinso, Ooan) — Imago | Imago | Octavia E. Butler | Oankali ooloi |
| Kalaf — Air | Air | Geoff Ryman | absent figure |
| Kalanu — American Gods | American Gods | Neil Gaiman | secondary character |
| Kali — The Years of Rice and Salt | The Years of Rice and Salt | Kim Stanley Robinson | New student / closing figure |
| Kalidasa — The Fountains of Paradise | The Fountains of Paradise | Arthur C. Clarke | historical antagonist / parallel figure |
| Kaliq — Adulthood Rites | Adulthood Rites | Octavia E. Butler | Raider |
| Kaliq — Imago | Imago | Octavia E. Butler | Human raider |
| Kallusin — The Foundation Trilogy | The Foundation Trilogy | Isaac Asimov | Calvinian robot / organizer |
| Kalr Eight — Ancillary Sword | Ancillary Sword | Ann Leckie | Attending soldier |
| Kalr Five(Five) — Ancillary Sword | Ancillary Sword | Ann Leckie | Breq's attending soldier |
| Kalr Twelve(Twelve) — Ancillary Sword | Ancillary Sword | Ann Leckie | Attending soldier |
| Kang(Kang Tongbi, Widow Kang) — The Years of Rice and Salt | The Years of Rice and Salt | Kim Stanley Robinson | POV character, scholar-poet |
| Kannika — The Windup Girl | The Windup Girl | Paolo Bacigalupi | Bar performer, antagonist |
| Kanya(General) — The Windup Girl | The Windup Girl | Paolo Bacigalupi | Environment Ministry captain, double agent |
| Kar'uchai(Kar'uchai Sukhtu-h'k Vaijhin-khi-khi) — Perdido Street Station | Perdido Street Station | China Miéville | Garuda hunter |
| Kareen(Lady Kareen, Kareen Koudelka) — Mirror Dance | Mirror Dance | Lois McMaster Bujold | actantial:object |
| Karellen(Supervisor, the Supervisor, Supervisor for Earth +1) — Childhood's End | Childhood's End | Arthur C. Clarke | Overlord Supervisor for Earth |
| Karen — Among Others | Among Others | Jo Walton | minor antagonist |
| Karen — Forever Peace | Forever Peace | Joe Haldeman | Platoon mechanic |
| Karen — Stand on Zanzibar | Stand on Zanzibar | John Brunner | vignette |
| Karen — Virtual Light | Virtual Light | William Gibson | Rydell's acquaintance/lover |
| Karime — Network Effect | Network Effect | Martha Wells | other |
| Karl Mercer(Karl, Hub Control) — Rendezvous with Rama | Rendezvous with Rama | Arthur C. Clarke | First officer / life-support authority |
| Karoll Rufirant(Rufirant) — Foundation's Edge | Foundation's Edge | Isaac Asimov | Hamish farmer |
| Karra — The Fifth Season | The Fifth Season | N.K. Jemisin | Tirimo comm member |
| Karrid(Karrid Arrage) — The Left Hand of Darkness | The Left Hand of Darkness | Ursula K. Le Guin | opponent (minor) |
| Kasei — Blue Mars | Blue Mars | Kim Stanley Robinson | Mixed-generation Martian guide |
| Kasei — Green Mars | Green Mars | Kim Stanley Robinson | Native Martian militant; Hiroko's son |
| Kasei — Red Mars | Red Mars | Kim Stanley Robinson | Underground driver, Michel's companion |
| Kaspar Hauser — The Evolution of Human Science | The Evolution of Human Science | Ted Chiang | Historical figure |
| Katharine — 1984 | 1984 | George Orwell | secondary character |
| Katharine Dahlman(Katharine) — Fledgling | Fledgling | Octavia E. Butler | Council Member / Accused Murderer |
| Kathy H.(Kath, I, Kathy) — Never Let Me Go | Never Let Me Go | Kazuo Ishiguro | Narrator and carer |
| Kathy Torrance — Idoru | Idoru | William Gibson | Slitscan executive/manager |
| Katin Crawford(Katin) — Nova | Nova | Samuel R. Delany | Scholar and aspiring novelist |
| Kault — The Uplift War | The Uplift War | David Brin | Thennanin diplomat, Uthacalthing's companion |
| Kawaresksenjajok(Kawa, the boy) — Ringworld | Ringworld | Larry Niven | helper |
| Keeper of the Great Seal — The Fifth Sally or The Mischief of King Balerion | The Fifth Sally or The Mischief of King Balerion | Stanislaw Lem | Official |
| Keeper of the Wampum(Keeper) — The Years of Rice and Salt | The Years of Rice and Salt | Kim Stanley Robinson | authority/revolutionary |
| Keepiru(Wormhole-Pilot) — Startide Rising | Startide Rising | David Brin | Neo-dolphin pilot |
| Keffers — Never Let Me Go | Never Let Me Go | Kazuo Ishiguro | Caretaker at the Cottages |
| Keiko Mitsuri — Rainbows End | Rainbows End | Vernor Vinge | Alliance cell member |
| Keith Alan Blackwell(Tazzie, The one-eared man, Blackwell +1) — Idoru | Idoru | William Gibson | Rez's security chief |
| Keiver — Use of Weapons | Use of Weapons | Iain M. Banks | Noble/Advisor in besieged castle |
| Kelenli — The Stone Sky | The Stone Sky | N. K. Jemisin | Mentor figure (Syl Anagist flashback) |
| Kelly Ek(Kelly) — Cyteen | Cyteen | C. J. Cherryh | helper |
| Kelso Pepper(Kelso, Captain Pepper) — Take Back Plenty | Take Back Plenty | Colin Greenland | antagonist |
| Kelvin(Kris, Narrator) — Solaris | Solaris | Stanislaw Lem | Newly arrived scientist and narrator |
| Kemnitz — Three Versions of Judas | Three Versions of Judas | Jorge Luis Borges | Theologian |
| Ken Wilson — The Separation | The Separation | Christopher Priest | Red Cross colleague |
| Keng — The Dispossessed | The Dispossessed | Ursula K. Le Guin | Terran Ambassador |
| Kenisi — Ammonite | Ammonite | Nicola Griffith | helper |
| Kenneth Turvey(Turvey) — Virtual Light | Virtual Light | William Gibson | Hostage-taker |
| Kenzie Walkiewicz(Special Communications Officer, Interim Minor Senator Kenzie Walkiewicz) — Perhaps the Stars | Perhaps the Stars | Ada Palmer | Child inventor |
| Kerala(the Kerala) — The Years of Rice and Salt | The Years of Rice and Salt | Kim Stanley Robinson | Military and political leader of Travancore |
| KerlaTinde — The Snow Queen | The Snow Queen | Joan D. Vinge | Antagonist-minor / officer |
| Keteng(Director Keteng) — Stand on Zanzibar | Stand on Zanzibar | John Brunner | Yatakangi government press director |
| Kev — Dreamsnake | Dreamsnake | Vonda N. McIntyre | Minor helper |
| Kevin — Anxiety Is the Dizziness of Freedom | Anxiety Is the Dizziness of Freedom | Ted Chiang | Support Group Member |
| Khalid — Cyteen | Cyteen | C. J. Cherryh | actantial opponent |
| Khalid(Old One-Hand) — The Years of Rice and Salt | The Years of Rice and Salt | Kim Stanley Robinson | Natural philosopher and alchemist |
| Kheim(Admiral Kheim) — The Years of Rice and Salt | The Years of Rice and Salt | Kim Stanley Robinson | Admiral, POV character |
| Khouri — Revelation Space | Revelation Space | Alastair Reynolds | Assassin and former soldier |
| Kiefer — Timescape | Timescape | Gregory Benford | Scripps scientist / California contact |
| Killing Time — Excession | Excession | Iain M. Banks | Warship / ROU |
| Kinet(Caracortada) — Dune | Dune | Frank Herbert | opponent |
| king(high king) — Tlön, Uqbar, Orbis Tertius | Tlön, Uqbar, Orbis Tertius | Jorge Luis Borges | Ruler |
| King(Your Royal Highness, Gracious Sovereign) — The Cyberiad | The Cyberiad | Stanislaw Lem | Sovereign |
| King Atrocitus — The Cyberiad | The Cyberiad | Stanislaw Lem | Sovereign |
| King Atrocitus(Atrocitus) — The First Sally or The Trap of Gargantius | The First Sally or The Trap of Gargantius | Stanislaw Lem | Monarch of Atrocia |
| King Balerion(His Royal Highness) — The Cyberiad | The Cyberiad | Stanislaw Lem | Sovereign of Cymberia |
| King Coyote — The Diamond Age | The Diamond Age | Neal Stephenson | opponent/antagonist within Primer |
| King Enamuel(Enamuel) — The First Sally or The Trap of Gargantius | The First Sally or The Trap of Gargantius | Stanislaw Lem | Historical monarch |
| King Excelsius(monster Excelsius) — The Cyberiad | The Cyberiad | Stanislaw Lem | Sovereign |
| King Ferocitus — The Cyberiad | The Cyberiad | Stanislaw Lem | Sovereign |
| King Ferocitus(Ferocitus) — The First Sally or The Trap of Gargantius | The First Sally or The Trap of Gargantius | Stanislaw Lem | Monarch of the neighboring kingdom |
| King Genius(the King) — Tale of the Three Storytelling Machines of King Genius | Tale of the Three Storytelling Machines of King Genius | Stanislaw Lem | Monarch |
| King Genius(Your Majesty) — The Cyberiad | The Cyberiad | Stanislaw Lem | Sovereign |
| King Giant(the giant, king of plant eaters) — Ringworld | Ringworld | Larry Niven | helper |
| King Krool(the King, King of Ionid) — The Cyberiad | The Cyberiad | Stanislaw Lem | Sovereign |
| King Krool(His Boundless Kroolty, His Majesty, Mighty Sovereign) — The Second Sally or The Offer of King Krool | The Second Sally or The Offer of King Krool | Stanislaw Lem | Monarch |
| King Krool — The Third Sally or The Dragons of Probability | The Third Sally or The Dragons of Probability | Stanislaw Lem | Sovereign |
| King of Spain(His Most Catholic Majesty, Spain, Majesty) — The Will to Battle | The Will to Battle | Ada Palmer | European Monarch |
| King of Spain(Spain, His Majesty) — Too Like the Lightning | Too Like the Lightning | Ada Palmer | King of Spain |
| King Pfftius — The Third Sally or The Dragons of Probability | The Third Sally or The Dragons of Probability | Stanislaw Lem | Ruler of Trufflandria |
| King Protuberon Asteristicus(His Royal Highness, sovereign ruler of the sister globes of Aphelion and Perihelion, Beloved Sovereign +1) — The Fourth Sally or How Trurl Built a Femfatalatron | The Fourth Sally or How Trurl Built a Femfatalatron | Stanislaw Lem | Sovereign ruler |
| King Thumbscrew(Thumbscrew the Third) — The Cyberiad | The Cyberiad | Stanislaw Lem | Sovereign |
| King Thumbscrew the Third(Thumbscrew) — Tale of the Three Storytelling Machines of King Genius | Tale of the Three Storytelling Machines of King Genius | Stanislaw Lem | Listener |
| Kira Kôtsukéno Suké(teacher of court etiquette, the uncivil courtier) — The Form of the Sword | The Form of the Sword | Jorge Luis Borges | Courtier and antagonist |
| Kira Kôtsukéno Suké — Tlön, Uqbar, Orbis Tertius | Tlön, Uqbar, Orbis Tertius | Jorge Luis Borges | Courtier |
| Kiran — 2312 | 2312 | Kim Stanley Robinson | Earth Refugee |
| Kiran's cousins — 2312 | 2312 | Kim Stanley Robinson | Kidnappers |
| Kirana Fawwaz(Kirana, Kira) — The Years of Rice and Salt | The Years of Rice and Salt | Kim Stanley Robinson | Lecturer, intellectual, lover |
| Kirard Set(Elder Wayaways) — The Snow Queen | The Snow Queen | Joan D. Vinge | minor/court |
| Kitka — The Yiddish Policemen's Union | The Yiddish Policemen's Union | Michael Chabon | minor helper |
| Kitty Gbe(Mrs. Kitty Gbe) — Stand on Zanzibar | Stand on Zanzibar | John Brunner | Beninian education minister |
| Kivrin(Lady Katherine, Isabel, Katherine) — Doomsday Book | Doomsday Book | Connie Willis | Time-traveling history student, protagonist |
| Kiyoaki — The Years of Rice and Salt | The Years of Rice and Salt | Kim Stanley Robinson | helper |
| Kjet Svensndot(Group Captain Svensndot, Group Captain) — A Fire Upon the Deep | A Fire Upon the Deep | Vernor Vinge | secondary protagonist/military |
| Klapaucius — A Good Shellacking | A Good Shellacking | Stanislaw Lem | Constructor, deuteragonist/trickster |
| Klapaucius(distinguished constructor, great lord) — Altruizine or A True Account of How Bonhomius the Hermetic Hermit Tried to Bring About Universal Happiness | Altruizine or A True Account of How Bonhomius the Hermetic Hermit Tried to Bring About Universal Happiness | Stanislaw Lem | Mentor and inventor |
| Klapaucius(the constructor) — How the World Was Saved | How the World Was Saved | Stanislaw Lem | Constructor |
| Klapaucius — Tale of the Three Storytelling Machines of King Genius | Tale of the Three Storytelling Machines of King Genius | Stanislaw Lem | Constructor |
| Klapaucius(colleague, constructor, wise constructor) — The Cyberiad | The Cyberiad | Stanislaw Lem | Constructor and inventor |
| Klapaucius(constructor, wealthy foreigner, Police Commissioner) — The Fifth Sally or The Mischief of King Balerion | The Fifth Sally or The Mischief of King Balerion | Stanislaw Lem | Constructor and tactician |
| Klapaucius — The First Sally (A) or Trurl's Electronic Bard | The First Sally (A) or Trurl's Electronic Bard | Stanislaw Lem | Rival constructor |
| Klapaucius — The First Sally or The Trap of Gargantius | The First Sally or The Trap of Gargantius | Stanislaw Lem | Constructor |
| Klapaucius(Constructor) — The Second Sally or The Offer of King Krool | The Second Sally or The Offer of King Krool | Stanislaw Lem | Constructor |
| Klapaucius — The Seventh Sally or How Trurl's Own Perfection Led to No Good | The Seventh Sally or How Trurl's Own Perfection Led to No Good | Stanislaw Lem | moral interlocutor |
| Klapaucius — The Sixth Sally or How Trurl and Klapaucius Created a Demon | The Sixth Sally or How Trurl and Klapaucius Created a Demon | Stanislaw Lem | Wise constructor |
| Klapaucius — The Third Sally or The Dragons of Probability | The Third Sally or The Dragons of Probability | Stanislaw Lem | Constructor |
| Klapaucius — Trurl's Machine | Trurl's Machine | Stanislaw Lem | Helper / Constructor |
| Klara(Gelle-Klara Moynlin, Klara Moynlin) — Gateway | Gateway | Frederik Pohl | Love interest/Mentor |
| Klara(AF) — Klara and the Sun | Klara and the Sun | Kazuo Ishiguro | Narrator and Artificial Friend (AF) |
| Klaus — All Tomorrow's Parties | All Tomorrow's Parties | William Gibson | Virtual envoy |
| Klia Asgar — The Foundation Trilogy | The Foundation Trilogy | Isaac Asimov | mentalic fugitive / courier |
| Kly(the old man, the Major) — Barrayar | Barrayar | Lois McMaster Bujold | actantial helper/donor |
| Kohaku — Perhaps the Stars | Perhaps the Stars | Ada Palmer | Guide / Apparition |
| Kohj(The Akjai) — Imago | Imago | Octavia E. Butler | Akjai ooloi |
| Kokila — The Years of Rice and Salt | The Years of Rice and Salt | Kim Stanley Robinson | Protagonist (Book Two) |
| Kokwa — Exhalation | Exhalation | Ted Chiang | Storyteller |
| Kokwa — The Truth of Fact, the Truth of Feeling | The Truth of Fact, the Truth of Feeling | Ted Chiang | Tiv Storyteller |
| Konrad(gray-haired man, man in the long coat, the professor) — All Tomorrow's Parties | All Tomorrow's Parties | William Gibson | Mysterious figure |
| Kosala(Aunt Kosala, World Mother, Bryar) — Perhaps the Stars | Perhaps the Stars | Ada Palmer | Fleet commander for the Cousins/Alliance |
| Koudelka(Kou, Lieutenant Koudelka) — Barrayar | Barrayar | Lois McMaster Bujold | actantial helper |
| KR Aspundh(KR) — The Snow Queen | The Snow Queen | Joan D. Vinge | Donor / sibyl mentor |
| Krat(Fleet-Mother, Mistress) — Startide Rising | Startide Rising | David Brin | Soro grand admiral / antagonist |
| Kris Galasckja(Kris) — The Separation | The Separation | Christopher Priest | Rear gunner |
| Krishna — Lord of Light | Lord of Light | Roger Zelazny | helper |
| Kubera(Kubera the Fat) — Lord of Light | Lord of Light | Roger Zelazny | helper |
| Kudda — Stories of Your Life and Others | Stories of Your Life and Others | Ted Chiang | Cart puller on the tower |
| Kudda — Tower of Babylon | Tower of Babylon | Ted Chiang | Cart-puller and tower dweller |
| Kumiko — Mona Lisa Overdrive | Mona Lisa Overdrive | William Gibson | Daughter of a Yakuza boss / Exile |
| Kung(Kung Jianguo) — The Years of Rice and Salt | The Years of Rice and Salt | Kim Stanley Robinson | revolutionary leader/mentor |
| Kuno Mlatje — Odysseus of Ithaca | Odysseus of Ithaca | Stanislaw Lem | Fictional Author |
| Kuo(Major Kuo) — The Years of Rice and Salt | The Years of Rice and Salt | Kim Stanley Robinson | helper |
| Kuranosuké(councilor, Oishi Kuranosuké) — Tlön, Uqbar, Orbis Tertius | Tlön, Uqbar, Orbis Tertius | Jorge Luis Borges | Avenging leader |
| Kuwayama — Idoru | Idoru | William Gibson | Corporate Executive |
| Kvetur(Kvet) — The Dispossessed | The Dispossessed | Ursula K. Le Guin | Shevek's acquaintance |
| Kwan(Wing's-wife, Mrs Wing, Mrs Wing Kwan) — Air | Air | Geoff Ryman | Mae's closest ally |
| Ky — Snow Crash | Snow Crash | Neal Stephenson | actantial:helper |
| Ky — Use of Weapons | Use of Weapons | Iain M. Banks | Crew Member |
| Kya — The Years of Rice and Salt | The Years of Rice and Salt | Kim Stanley Robinson | Protagonist (interlude) |
| Kybernator Perlmutter(Perlmutter) — Take Back Plenty | Take Back Plenty | Colin Greenland | opponent |
| Kyle — Exhalation | Exhalation | Ted Chiang | Ana's partner |
| Kyle — The Lifecycle of Software Objects | The Lifecycle of Software Objects | Ted Chiang | Ana's boyfriend |
| Kynes(doctor Kynes, el planetólogo, Liet +3) — Dune | Dune | Frank Herbert | Son of Kynes, Imperial Planetologist, Fremen Naib |
| Kyu — The Years of Rice and Salt | The Years of Rice and Salt | Kim Stanley Robinson | Protagonist (bardo passage) |
| L. Bob Rife(Rife) — Snow Crash | Snow Crash | Neal Stephenson | actantial:opponent |
| L. Evans — U-Write-It | U-Write-It | Stanislaw Lem | Journalist/Critic |
| L.C.(Lucy Clare Beckett, Luz, Lucy Clare +2) — Lost Futures | Lost Futures | Lisa Tuttle | Clare-variant / alternate self |
| La Lujanera — Tlön, Uqbar, Orbis Tertius | Tlön, Uqbar, Orbis Tertius | Jorge Luis Borges | Rosendo's Woman |
| Lady Caroline — Blackout/All Clear | Blackout/All Clear | Connie Willis | Manor owner |
| Lady dy Hueltar — Paladin of Souls | Paladin of Souls | Lois McMaster Bujold | opponent |
| Lady Imeyne(the mother-in-law, the old woman, Imeyne +1) — Doomsday Book | Doomsday Book | Connie Willis | Medieval noblewoman; suspicious observer |
| Lady Schrapnell — To Say Nothing of the Dog | To Say Nothing of the Dog | Connie Willis | Institutional antagonist/patron |
| Lady Tichborne(Tichborne) — Tlön, Uqbar, Orbis Tertius | Tlön, Uqbar, Orbis Tertius | Jorge Luis Borges | Grieving Mother |
| LaFarge(Anna, the old woman, the old man) — The Martian Chronicles | The Martian Chronicles | Ray Bradbury | protagonist |
| Lagos — Snow Crash | Snow Crash | Neal Stephenson | sender |
| Laia Asieo Odo(Odo) — The Dispossessed | The Dispossessed | Ursula K. Le Guin | Historical Figure |
| Laila — The Years of Rice and Salt | The Years of Rice and Salt | Kim Stanley Robinson | Bahram's daughter |
| Laliskareerlyar — Ringworld | Ringworld | Larry Niven | helper |
| Landlord (unnamed)(superintendent of Genly's island) — The Left Hand of Darkness | The Left Hand of Darkness | Ursula K. Le Guin | minor/helper |
| Laney — All Tomorrow's Parties | All Tomorrow's Parties | William Gibson | Data-miner |
| Langdale — Stories of Your Life and Others | Stories of Your Life and Others | Ted Chiang | Student |
| Lankowski — Ender's Game | Ender's Game | Orson Scott Card | Pan-Islamic intelligence operative |
| Lao Gu — The Windup Girl | The Windup Girl | Paolo Bacigalupi | Anderson's rickshaw man / Hock Seng's informant |
| Larril — Dreamsnake | Dreamsnake | Vonda N. McIntyre | minor |
| Larry — Stranger in a Strange Land | Stranger in a Strange Land | Robert A. Heinlein | Member of Harshaw's household |
| Lars Peter Engström — Three Versions of Judas | Three Versions of Judas | Jorge Luis Borges | Theologian |
| LaRue(Chief of Protocol) — Stranger in a Strange Land | Stranger in a Strange Land | Robert A. Heinlein | Protocol official |
| Lashar — The Stone Sky | The Stone Sky | N. K. Jemisin | Found Moon orogene child |
| Latimer — Doomsday Book | Doomsday Book | Connie Willis | Oxford colleague |
| Laughing Chan(Ah Chan) — The Windup Girl | The Windup Girl | Paolo Bacigalupi | Yellow card doctor / helper |
| Laura(Laura Moon, Babe, Puppy (used by Shadow toward her)) — American Gods | American Gods | Neil Gaiman | Shadow's deceased wife |
| Laura — Never Let Me Go | Never Let Me Go | Kazuo Ishiguro | Carer |
| Laura — Timescape | Timescape | Gregory Benford | minor character |
| Laura Ernst(Surgeon-Commander Ernst, Laura, Doc) — Rendezvous with Rama | Rendezvous with Rama | Arthur C. Clarke | Ship's doctor / field expedition leader |
| Laura Jean — Lost Futures | Lost Futures | Lisa Tuttle | Clare's mother |
| Laurel — Lost Futures | Lost Futures | Lisa Tuttle | Clare's cousin |
| Laurian — A Closed and Common Orbit | A Closed and Common Orbit | Becky Chambers | companion |
| Laurie Jo Bear — The Yiddish Policemen's Union | The Yiddish Policemen's Union | Michael Chabon | backstory figure |
| Lawrence Sutton — Stories of Your Life and Others | Stories of Your Life and Others | Ted Chiang | 4th-year student |
| Lazarus Morell(Morell) — The Circular Ruins | The Circular Ruins | Jorge Luis Borges | Criminal gang leader |
| Lazarus Morell — The Form of the Sword | The Form of the Sword | Jorge Luis Borges | Criminal, slave trader |
| Lazarus Morell — Tlön, Uqbar, Orbis Tertius | Tlön, Uqbar, Orbis Tertius | Jorge Luis Borges | Criminal / Preacher |
| Leaf-eater — Speaker for the Dead | Speaker for the Dead | Orson Scott Card | Piggy faction leader / opponent |
| Leah — Adulthood Rites | Adulthood Rites | Octavia E. Butler | Human woman in Lo |
| Leah — Among Others | Among Others | Jo Walton | minor |
| Leah Bede(Leah) — Dawn | Dawn | Octavia E. Butler | Human survivor |
| Leah Bede(Leah) — Imago | Imago | Octavia E. Butler | Human survivor |
| Leech — The Third Sally or The Dragons of Probability | The Third Sally or The Dragons of Probability | Stanislaw Lem | Scientist |
| Leffid Ispanteli(Leffid) — Excession | Excession | Iain M. Banks | Festival attendee |
| Leifin — Ammonite | Ammonite | Nicola Griffith | helper |
| Leigh Hunt(M. Hunt, Hunt) — The Fall of Hyperion | The Fall of Hyperion | Dan Simmons | Gladstone's chief advisor and aide |
| Lellius — Excession | Excession | Iain M. Banks | Vice-consul |
| Lemuel Pigeon(Lemuel, Pigeon, Lem) — Perdido Street Station | Perdido Street Station | China Miéville | Underworld intermediary |
| Lena Gu(Mistress Gu, Lena) — Rainbows End | Rainbows End | Vernor Vinge | supporting |
| Lenore — The Moon Is a Harsh Mistress | The Moon Is a Harsh Mistress | Robert A. Heinlein | Davis family wife |
| Lenton — I, Robot | I, Robot | Isaac Asimov | Byerley's campaign manager |
| Leo — Nova | Nova | Samuel R. Delany | Net-rider / Fisherman |
| Leon — The Peripheral | The Peripheral | William Gibson | Army veteran / Friend |
| Leon Elai(Dr. Leon Elai) — Stand on Zanzibar | Stand on Zanzibar | John Brunner | Beninian foreign affairs minister |
| Leon Greco(I, GRECO) — Understand | Understand | Ted Chiang | Protagonist |
| Leonard Cheshire(Pilot Officer Leonard Cheshire, DSO DFC) — The Separation | The Separation | Christopher Priest | RAF bomber pilot; later Operation Maccabeus volunteer |
| Leonide(Supervisor Leonide) — Network Effect | Network Effect | Martha Wells | Barish-Estranza corporate supervisor |
| Lerna — The Fifth Season | The Fifth Season | N.K. Jemisin | Doctor |
| Lerna — The Stone Sky | The Stone Sky | N. K. Jemisin | Physician / Companion |
| Leroy Pluckett(Dr. Pluckett) — The Calculating Stars | The Calculating Stars | Mary Robinette Kowal | antagonist |
| Lesley(Lesley Juniper Sniper Saneer, Acting O.S.) — The Will to Battle | The Will to Battle | Ada Palmer | Acting Assassin |
| Lestim Gianni — Foundation's Edge | Foundation's Edge | Isaac Asimov | Speaker of the Second Foundation |
| Letizia Alvarez de Toledo — The Library of Babel | The Library of Babel | Jorge Luis Borges | Theorist |
| Letizia Alvarez de Toledo — Tlön, Uqbar, Orbis Tertius | Tlön, Uqbar, Orbis Tertius | Jorge Luis Borges | Theorist |
| Leto(el Duque, Duke Leto) — Dune | Dune | Frank Herbert | actantial:subject |
| Lev Zubov(Lev) — Agency | Agency | William Gibson | Wealthy associate |
| Lev Zubov(Lev) — The Peripheral | The Peripheral | William Gibson | Continua hobbyist / Klept heir |
| Lianna(Lee, Lianna Lutterodt) — Echopraxia | Echopraxia | Peter Watts | Crew member / Informant |
| Libo — Speaker for the Dead | Speaker for the Dead | Orson Scott Card | Zenador apprentice, Pipo's son |
| Liddell Hart — The Garden of Forking Paths | The Garden of Forking Paths | Jorge Luis Borges | Historian |
| Lieutenant — Snow Crash | Snow Crash | Neal Stephenson | actantial:helper |
| Lieutenant Awn — Ancillary Justice | Ancillary Justice | Ann Leckie | Junior officer / focal character in flashback |
| Lieutenant Dariet Suleir(Lieutenant Dariet) — Ancillary Justice | Ancillary Justice | Ann Leckie | actantial:helper |
| Lieutenant Ekalu(Amaat One (former)) — Ancillary Sword | Ancillary Sword | Ann Leckie | Officer |
| Lieutenant Issaaia — Ancillary Justice | Ancillary Justice | Ann Leckie | actantial:opponent |
| Lieutenant Iverson — Mirror Dance | Mirror Dance | Lois McMaster Bujold | bureaucracy |
| Lieutenant Khoroshen — Starship Troopers | Starship Troopers | Robert A. Heinlein | helper/superior officer |
| Lieutenant Kimura — Mirror Dance | Mirror Dance | Lois McMaster Bujold | minor officer |
| Lieutenant Skaaiat(Inspector Supervisor Skaaiat Awer) — Ancillary Justice | Ancillary Justice | Ann Leckie | secondary character (flashback) |
| Lieutenant Talbot — The Coral Bones | The Coral Bones | Jynne Martin | Ship's officer |
| Ligaya(Li) — The Coral Bones | The Coral Bones | Jynne Martin | Telma's deceased daughter |
| Lila — Blackout/All Clear | Blackout/All Clear | Connie Willis | Shelter regular |
| Lilith(Lilith Iyapo) — Adulthood Rites | Adulthood Rites | Octavia E. Butler | Akin's Human mother |
| Lilith(Mother, Lilith Iyapo, Judas goat) — Imago | Imago | Octavia E. Butler | Human leader and intermediary |
| Lilith Iyapo(Lilith) — Dawn | Dawn | Octavia E. Butler | Leader of the human survivors |
| Lilly Junior(the Durona clone-girl) — Mirror Dance | Mirror Dance | Lois McMaster Bujold | actantial:object |
| Lin(Ms. Lin) — Perdido Street Station | Perdido Street Station | China Miéville | Khepri artist, Isaac's lover |
| Lincoln Powell(Dishonest Abe, Linc, Powell +1) — The Demolished Man | The Demolished Man | Alfred Bester | detective/antagonist-to-Reich |
| Linda Lee — Neuromancer | Neuromancer | William Gibson | Case's dead girlfriend |
| Linge Chen(Chief Commissioner) — The Foundation Trilogy | The Foundation Trilogy | Isaac Asimov | Chief Commissioner / de facto galactic ruler |
| Linna — Blackout/All Clear | Blackout/All Clear | Connie Willis | Lab assistant |
| Lionel — Stories of Your Life and Others | Stories of Your Life and Others | Ted Chiang | Robert's friend |
| Lionel Dacey(Edmund) — Dacey's Patent Automatic Nanny | Dacey's Patent Automatic Nanny | Ted Chiang | Mathematician and son of Reginald Dacey |
| Liono Kodell(Director Kodell, Director of Security, Liono +2) — Foundation's Edge | Foundation's Edge | Isaac Asimov | Bureaucratic antagonist / Branno's instrument |
| Lisma Gunawan — Exhalation | Exhalation | Ted Chiang | Forum user |
| Liss — Paladin of Souls | Paladin of Souls | Lois McMaster Bujold | helper |
| Little doctor — Use of Weapons | Use of Weapons | Iain M. Banks | Surgeon/Entertainer |
| Livio — Snow Crash | Snow Crash | Neal Stephenson | helper |
| Livueta — Use of Weapons | Use of Weapons | Iain M. Banks | Sister of Cheradenine |
| Lo — Imago | Imago | Octavia E. Butler | Living entity/Town |
| Lodovik Trema(Rissik Numant, Lodovik) — The Foundation Trilogy | The Foundation Trilogy | Isaac Asimov | Three-Laws-free humaniform robot / protagonist |
| Lofty(John Skinner, Warrant Officer John Skinner) — The Separation | The Separation | Christopher Priest | Flight engineer |
| Loki(Low Key Lyesmith) — American Gods | American Gods | Neil Gaiman | antagonist (new gods) |
| Lolly — The Lifecycle of Software Objects | The Lifecycle of Software Objects | Ted Chiang | Digient |
| Lord Fieldhurst(Fieldhurst, the earl) — Stories of Your Life and Others | Stories of Your Life and Others | Ted Chiang | Researcher |
| Lord Finkle-McGraw(Lord Alexander Chung-Sik Finkle-McGraw) — The Diamond Age | The Diamond Age | Neal Stephenson | Equity Lord / Primer commissioner |
| Lord High Chancellor — The Fifth Sally or The Mischief of King Balerion | The Fifth Sally or The Mischief of King Balerion | Stanislaw Lem | Courtier |
| Lord Protozor(Master of the Royal Hunt) — The Cyberiad | The Cyberiad | Stanislaw Lem | Official |
| Lord Protozor(Master of the Royal Hunt, emissary) — The Second Sally or The Offer of King Krool | The Second Sally or The Offer of King Krool | Stanislaw Lem | Emissary / Master of the Royal Hunt |
| Lord Vorsmythe — Mirror Dance | Mirror Dance | Lois McMaster Bujold | actantial:helper |
| Lorelei Cook(Minister Cook) — Perhaps the Stars | Perhaps the Stars | Ada Palmer | Nurturist Leader and Minister |
| Lorelei Cook(Cookie, Minister Cook, Minister of Education +1) — The Will to Battle | The Will to Battle | Ada Palmer | Minister |
| Lori Harber — Stories of Your Life and Others | Stories of Your Life and Others | Ted Chiang | 3rd-year student at Maxwell College |
| Lorq Von Ray(Captain Von Ray, Lorq, Captain +3) — Nova | Nova | Samuel R. Delany | Captain of the Roc / The Black Cockatoo |
| Losten — The Gods Themselves | The Gods Themselves | Isaac Asimov | Hard One mentor |
| Louis Wu(Louis, Luweewu) — Ringworld | Ringworld | Larry Niven | protagonist |
| Louise Banks(Louise, Mom, Dr. Banks) — Stories of Your Life and Others | Stories of Your Life and Others | Ted Chiang | Linguist and mother |
| Louise Banks(I, Mom, Dr. Banks) — Story of Your Life | Story of Your Life | Ted Chiang | Narrator and Linguist |
| Louise Forehand — Gateway | Gateway | Frederik Pohl | Acquaintance/Prospector trainee |
| Loveless(Smiley, the cowboy fucker) — Virtual Light | Virtual Light | William Gibson | Assassin / Enforcer |
| Lowell — Virtual Light | Virtual Light | William Gibson | Chevette's ex-boyfriend |
| Lower Court Official(Native) — The Third Sally or The Dragons of Probability | The Third Sally or The Dragons of Probability | Stanislaw Lem | Trufflandrian subject |
| Lowry(Jimmy Boy, Jim, Old Jim) — Acceptance | Acceptance | Jeff VanderMeer | Southern Reach Manipulator / First Expedition Survivor |
| Lowry — Authority | Authority | Jeff VanderMeer | Central Official / Expedition Survivor |
| Lu Wai(the Mirror, Sergeant Lu Wai) — Ammonite | Ammonite | Nicola Griffith | Sublieutenant; Dogias's partner |
| Luba Luft(Miss Luft) — Do Androids Dream of Electric Sheep? | Do Androids Dream of Electric Sheep? | Philip K. Dick | actantial:opponent |
| Lublamai(Lub) — Perdido Street Station | Perdido Street Station | China Miéville | Isaac's labmate, victim |
| Lucian Greenaway(Mr. Greenaway, Greenaway) — Pattern Recognition | Pattern Recognition | William Gibson | Antique dealer |
| Lucky Gazid(Gazid, Lucky) — Perdido Street Station | Perdido Street Station | China Miéville | Drug supplier |
| Lucky Kaa — Startide Rising | Startide Rising | David Brin | Neo-dolphin pilot on Streaker |
| Lucy — The Windup Girl | The Windup Girl | Paolo Bacigalupi | Minor farang figure |
| Lucy Nguyen — The Windup Girl | The Windup Girl | Paolo Bacigalupi | Farang expatriate |
| Lugatum — Tower of Babylon | Tower of Babylon | Ted Chiang | Cart-puller |
| Luis — Imago | Imago | Octavia E. Butler | Guard |
| Luis Irala — Tlön, Uqbar, Orbis Tertius | Tlön, Uqbar, Orbis Tertius | Jorge Luis Borges | Carpenter/Friend |
| Luke — The Handmaid's Tale | The Handmaid's Tale | Margaret Atwood | Offred's husband from before Gilead |
| Lung(Lieutenant Chung Lung, chungl@arm) — Air | Air | Geoff Ryman | Mae's son |
| Luo(Minister Luo, Minister of Public Safety) — The Will to Battle | The Will to Battle | Ada Palmer | Minister of Public Safety |
| Lupus Yonderboy(Yonder boy) — Neuromancer | Neuromancer | William Gibson | Panther Modern leader |
| Lustig — The Martian Chronicles | The Martian Chronicles | Ray Bradbury | Crew, Third Expedition |
| Lusuna — Nova | Nova | Samuel R. Delany | University student |
| Luther — The Calculating Stars | The Calculating Stars | Mary Robinette Kowal | minor |
| Lydia McCue(Lieutenant McCue) — The Uplift War | The Uplift War | David Brin | Marine lieutenant, Prathachulthorn's second-in-command |
| Lyle — Anxiety Is the Dizziness of Freedom | Anxiety Is the Dizziness of Freedom | Ted Chiang | Support Group Member |
| Lyle — Exhalation | Exhalation | Ted Chiang | Support Group Member |
| Lynceos — Nova | Nova | Samuel R. Delany | Cyborg stud |
| Lynch — Count Zero | Count Zero | William Gibson | Mercenary |
| Lynn — The Calculating Stars | The Calculating Stars | Mary Robinette Kowal | minor |
| Macon — The Peripheral | The Peripheral | William Gibson | Technical coordinator |
| Macro(Mac Roman) — Forever Peace | Forever Peace | Joe Haldeman | Physics department chair, covert antagonist |
| Macy O'Toole — Stand on Zanzibar | Stand on Zanzibar | John Brunner | GT junior VP, procurement |
| Macy Wilton(Kolina, Macy) — Adulthood Rites | Adulthood Rites | Octavia E. Butler | Resister |
| Mad Bear(Hongan Os) — A Canticle for Leibowitz | A Canticle for Leibowitz | Walter M. Miller, Jr. | Minor antagonist |
| Mad Sweeney — American Gods | American Gods | Neil Gaiman | helper/trickster |
| Madam Sururi(the seer, the fake guru) — The Years of Rice and Salt | The Years of Rice and Salt | Kim Stanley Robinson | soul-cluster member |
| Madame(Marie-Claude) — Never Let Me Go | Never Let Me Go | Kazuo Ishiguro | External visitor to Hailsham |
| Madame — Seven Surrenders | Seven Surrenders | Ada Palmer | Brothel Proprietor / Powerbroker |
| Madame de Sade(Madame, Madame D'Arouet) — Too Like the Lightning | Too Like the Lightning | Ada Palmer | Club proprietor |
| Madame Iritosky — To Say Nothing of the Dog | To Say Nothing of the Dog | Connie Willis | Fraudulent medium |
| Madame Ping — The Diamond Age | The Diamond Age | Neal Stephenson | Entertainment entrepreneur |
| Madame Szegeczowska — I, Robot | I, Robot | Isaac Asimov | European Region Vice-Co-ordinator |
| Madame Vesant(Becky Vesey, Allie) — Stranger in a Strange Land | Stranger in a Strange Land | Robert A. Heinlein | Minor / Thematic foil |
| Madison — Agency | Agency | William Gibson | Information Broker |
| Mae(Chung Mae, Mrs Chung-ma'am, Madam Owl +9) — Air | Air | Geoff Ryman | Protagonist |
| Maedda(Tuio) — The Dispossessed | The Dispossessed | Ursula K. Le Guin | Rebel Leader |
| Maesch — A Perfect Vacuum | A Perfect Vacuum | Stanislaw Lem | Condemned man |
| Magda — Pattern Recognition | Pattern Recognition | William Gibson | Design student and marketer |
| Magesta Barbile(Doctor Barbile, Barbile) — Perdido Street Station | Perdido Street Station | China Miéville | Clerk / Contact |
| Maggie Gee — The Calculating Stars | The Calculating Stars | Mary Robinette Kowal | other |
| Mahalia Geary(John, Fulana Detail, Marya +2) — The City & The City | The City & The City | China Miéville | Parents of the victim |
| Mahanayake Thero(Venerable Bodhidharma, Maha Thero) — The Fountains of Paradise | The Fountains of Paradise | Arthur C. Clarke | Opponent / Religious authority |
| Mahesh — Exhalation | Exhalation | Ted Chiang | Blue Gamma employee |
| Mahit Dzmare(the barbarian, Ambassador, Dzmare +1) — A Desolation Called Peace | A Desolation Called Peace | Arkady Martine | Former Lsel Station Ambassador; first-contact linguist |
| Mahmood — Echopraxia | Echopraxia | Peter Watts | Bicameral node |
| Mahmoud(Stinky, Dr. Mahmoud) — Stranger in a Strange Land | Stranger in a Strange Land | Robert A. Heinlein | Linguist and water-brother |
| Mai — The Windup Girl | The Windup Girl | Paolo Bacigalupi | Sick factory girl / witness |
| Maia — Childhood's End | Childhood's End | Arthur C. Clarke | Rupert's partner |
| Maia Duvall(Maia, Duvall) — Redshirts | Redshirts | John Scalzi | Ensign, core group member |
| Maimuna — The Merchant and the Alchemist's Gate | The Merchant and the Alchemist's Gate | Ted Chiang | Assistant to the physicians |
| Maisry — Doomsday Book | Doomsday Book | Connie Willis | secondary |
| Maitland — Blackout/All Clear | Blackout/All Clear | Connie Willis | FANY colleague |
| Major Bloch — Stranger in a Strange Land | Stranger in a Strange Land | Robert A. Heinlein | S.S. officer |
| Major General Prchl(Lieutenant General Prchl) — De Impossibilitate Vitae / De Impossibilitate Prognoscendi | De Impossibilitate Vitae / De Impossibilitate Prognoscendi | Stanislaw Lem | Imperial Crown Commissariat |
| Major General Stanton Roser(Assistant Secretary for Force Management and Personnel) — Forever Peace | Forever Peace | Joe Haldeman | sender/hidden leader |
| Major Namm — The Foundation Trilogy | The Foundation Trilogy | Isaac Asimov | Palace security officer |
| Major Prathachulthorn(Pratha-chulthorn) — The Uplift War | The Uplift War | David Brin | Human Marine officer, resistance commander |
| Major Reid — Starship Troopers | Starship Troopers | Robert A. Heinlein | supporting |
| Makanee — Startide Rising | Startide Rising | David Brin | Ship's physician (neo-dolphin) |
| Makatiel — Hell Is the Absence of God | Hell Is the Absence of God | Ted Chiang | Angel |
| Malaputz(Malapusticus Pandemonius) — Tale of the Three Storytelling Machines of King Genius | Tale of the Three Storytelling Machines of King Genius | Stanislaw Lem | Prisoner |
| Male Human — Imago | Imago | Octavia E. Butler | Human survivor |
| Malgara — The Fountains of Paradise | The Fountains of Paradise | Arthur C. Clarke | historical antagonist |
| Malouf(Halim Malouf) — The Calculating Stars | The Calculating Stars | Mary Robinette Kowal | helper |
| Mama-ji(Kali) — American Gods | American Gods | Neil Gaiman | Opponent within coalition |
| Man(Kahn, the Man, the Woman) — The Forever War | The Forever War | Joe Haldeman | Post-war collective entity |
| Man at the window / Party host — Use of Weapons | Use of Weapons | Iain M. Banks | Political figure or operative in Solotol |
| Man in charcoal suit(Mr. World (implied)) — American Gods | American Gods | Neil Gaiman | opponent |
| Man in the wire-filament mask — Stars in My Pocket Like Grains of Sand | Stars in My Pocket Like Grains of Sand | Samuel R. Delany | Institute Official |
| Man with the camera — All Tomorrow's Parties | All Tomorrow's Parties | William Gibson | Hit team leader |
| Man with the glass eye — Snow Crash | Snow Crash | Neal Stephenson | helper |
| Man with the tanto(the professor, guy with the black leather car-coat) — All Tomorrow's Parties | All Tomorrow's Parties | William Gibson | Assassin |
| Manager — Klara and the Sun | Klara and the Sun | Kazuo Ishiguro | Former store manager |
| Mandachuva — Speaker for the Dead | Speaker for the Dead | Orson Scott Card | Piggy helper/interpreter |
| Mandrillion(King Mandrillion, His Royal Highness) — The Cyberiad | The Cyberiad | Stanislaw Lem | Ruler of the Multitudians |
| Manjiri — A Closed and Common Orbit | A Closed and Common Orbit | Becky Chambers | helper |
| Mannie(Man, Manuel, Bork +6) — The Moon Is a Harsh Mistress | The Moon Is a Harsh Mistress | Robert A. Heinlein | Protagonist and narrator; computer technician and reluctant revolutionary |
| Manoukhian — Revelation Space | Revelation Space | Alastair Reynolds | Operative |
| Mantagnes(Chief Inspector) — The Snow Queen | The Snow Queen | Joan D. Vinge | Antagonist subordinate, bureaucratic rival |
| Manuela — Agency | Agency | William Gibson | Verity's friend |
| Manuzhai — The Sparrow | The Sparrow | Mary Doria Russell | Runa host |
| Mapes — Dune | Dune | Frank Herbert | other |
| Mara(Lord of Illusion, Aram) — Lord of Light | Lord of Light | Roger Zelazny | Opponent / Infiltrator |
| Marac — Ammonite | Ammonite | Nicola Griffith | Aoife's daughter |
| Marc Corey — Redshirts | Redshirts | John Scalzi | 21st-century actor playing Kerensky |
| Marc Esposito — Stories of Your Life and Others | Stories of Your Life and Others | Ted Chiang | 4th-year student at Waterston College |
| Marc Lobell — Forever Peace | Forever Peace | Joe Haldeman | helper |
| Marc Robichaux(Marc) — The Sparrow | The Sparrow | Mary Doria Russell | Jesuit naturalist, de facto Father Superior |
| Marcão(Marcos Ribeira, Cão, Marcos Maria Ribeira +1) — Speaker for the Dead | Speaker for the Dead | Orson Scott Card | Colony worker, future husband of Novinha |
| Marcasite — The Fifth Season | The Fifth Season | N.K. Jemisin | Instructor |
| Marcel Coscat — A Perfect Vacuum | A Perfect Vacuum | Stanislaw Lem | Fictional Author |
| Marcel Coscat(Monsieur Coscat) — Les Robinsonades | Les Robinsonades | Stanislaw Lem | Author |
| Marcelo Yarmolinsky — Tlön, Uqbar, Orbis Tertius | Tlön, Uqbar, Orbis Tertius | Jorge Luis Borges | Victim / Writer |
| Marco — Cyteen | Cyteen | C. J. Cherryh | Security / systems programmer |
| Marco — Exhalation | Exhalation | Ted Chiang | Neuroblast digient |
| Marco — The Lifecycle of Software Objects | The Lifecycle of Software Objects | Ted Chiang | Neuroblast digient |
| Marco Metz(the gloveman, the musician) — Take Back Plenty | Take Back Plenty | Colin Greenland | Musician, leader of Contraband |
| Marcus Apollo(the papal nuncio, the nuncio) — A Canticle for Leibowitz | A Canticle for Leibowitz | Walter M. Miller, Jr. | actantial:receiver |
| Marcus Flaminius Rufus — The Form of the Sword | The Form of the Sword | Jorge Luis Borges | Military tribune |
| Maree(the blonde clone) — Mirror Dance | Mirror Dance | Lois McMaster Bujold | actantial:object |
| Margaret Braithwaite(Margaret, Joan) — Fledgling | Fledgling | Octavia E. Butler | Shori's advocate |
| Margaret Smith — The Approach to Al-Mu'tasim | The Approach to Al-Mu'tasim | Jorge Luis Borges | Scholar |
| Margery — Queen of the States | Queen of the States | Lisa Goldstein | Helper / cunning woman |
| Marghe(John, Marghe Taishan, Marguerite Angelica Taishan +6) — Ammonite | Ammonite | Nicola Griffith | Protagonist / SEC anthropologist |
| Margit — Adulthood Rites | Adulthood Rites | Octavia E. Butler | Construct female |
| Margit — Imago | Imago | Octavia E. Butler | Construct sibling |
| Marguerite Olsen — American Gods | American Gods | Neil Gaiman | minor human |
| Maria Beaumont(The Gilt Corpse) — The Demolished Man | The Demolished Man | Alfred Bester | Pawn/hostess |
| Maria deSouza — Liking What You See: A Documentary | Liking What You See: A Documentary | Ted Chiang | 3rd-year student, President of the Students for Equality Everywhere (SEE) |
| Maria deSouza — Stories of Your Life and Others | Stories of Your Life and Others | Ted Chiang | Student representative / Advocate |
| Maria Zheng — Exhalation | Exhalation | Ted Chiang | Forum user |
| Mariam(Mrs Mack) — Air | Air | Geoff Ryman | Village woman |
| Marian — Blue Mars | Blue Mars | Kim Stanley Robinson | Revolutionary cell member |
| Marian — Red Mars | Red Mars | Kim Stanley Robinson | supporting |
| Marie Laveau(Widow Paris, pretty Marie) — American Gods | American Gods | Neil Gaiman | historical interlude secondary |
| Marietta — Snow Crash | Snow Crash | Neal Stephenson | opponent |
| Marika — De Impossibilitate Vitae / De Impossibilitate Prognoscendi | De Impossibilitate Vitae / De Impossibilitate Prognoscendi | Stanislaw Lem | Surgeon Kouska's former fiancée |
| Marina — Blue Mars | Blue Mars | Kim Stanley Robinson | Messenger / First Hundred survivor |
| Marina — Green Mars | Green Mars | Kim Stanley Robinson | First Hundred eco-economist |
| Marina — Imago | Imago | Octavia E. Butler | Human captive/guest |
| Marina — Red Mars | Red Mars | Kim Stanley Robinson | First Hundred member, news bearer |
| Marjorie(Miss Hayes) — Blackout/All Clear | Blackout/All Clear | Connie Willis | Shopgirl / helper |
| Mark Vorkosigan(the Countess, the Captain, Admiral Naismith +20) — Mirror Dance | Mirror Dance | Lois McMaster Bujold | Deuteragonist / Mark's progenitor |
| Markham(Greg, Gregory Markham, Jan) — Timescape | Timescape | Gregory Benford | Helper; theoretical physicist and intellectual mediator |
| Marlene — Division by Zero | Division by Zero | Ted Chiang | Carl's friend |
| Marly — Count Zero | Count Zero | William Gibson | Art investigator / Protagonist |
| Marq Dyeth(Marq, I, Skepta Marq +3) — Stars in My Pocket Like Grains of Sand | Stars in My Pocket Like Grains of Sand | Samuel R. Delany | Narrator / Protagonist |
| Marquis Châteauneuf du Pape — Gruppenfuhrer Louis XVI | Gruppenfuhrer Louis XVI | Stanislaw Lem | Master of ceremonies |
| Marsha(Marsha Gould) — Timescape | Timescape | Gregory Benford | supporting |
| Marsha Newmark — Count Zero | Count Zero | William Gibson | Bobby's mother |
| Marta — Stars in My Pocket Like Grains of Sand | Stars in My Pocket Like Grains of Sand | Samuel R. Delany | Medical/Investigative Official |
| Marta — The Form of the Sword | The Form of the Sword | Jorge Luis Borges | Artist / Rival |
| Martian girl (sand ship)(the girl, the vision) — The Martian Chronicles | The Martian Chronicles | Ray Bradbury | actantial:sender |
| Martin — 1984 | 1984 | George Orwell | minor |
| Martin Buber — The Sect of the Phoenix | The Sect of the Phoenix | Jorge Luis Borges | Cited authority (contrast point) |
| Martín Fierro(the stranger, the other man) — The End | The End | Jorge Luis Borges | Protagonist / fated killer |
| Martín Fierro(the deserter) — Tlön, Uqbar, Orbis Tertius | Tlön, Uqbar, Orbis Tertius | Jorge Luis Borges | Outlaw |
| Martin Guildbreaker(Guildbreaker, Mason, Martin +5) — Too Like the Lightning | Too Like the Lightning | Ada Palmer | Polylegal Investigator |
| Martin Harrison(Martin) — Fledgling | Fledgling | Octavia E. Butler | Symbiont to William Gordon |
| Martin Silenus — Hyperion | Hyperion | Dan Simmons | Dissolute poet/pilgrim narrator |
| Martin Silenus(Silenus) — The Fall of Hyperion | The Fall of Hyperion | Dan Simmons | Pilgrim / satirical poet |
| Marty(Mr. Larrin) — Forever Peace | Forever Peace | Joe Haldeman | Senior researcher, mentor figure |
| Martyn(Dad) — Network Effect | Network Effect | Martha Wells | helper |
| Marvel — Perhaps the Stars | Perhaps the Stars | Ada Palmer | Crewmate |
| Mary — Blue Mars | Blue Mars | Kim Stanley Robinson | Engineer / settler |
| Mary(Dr. Mary Ahrens, Dr. Ahrens, Great-Aunt Mary) — Doomsday Book | Doomsday Book | Connie Willis | Senior physician; Dunworthy's ally |
| Mary — Stand on Zanzibar | Stand on Zanzibar | John Brunner | vignette |
| Mary(Minister Murphy) — The Ministry for the Future | The Ministry for the Future | Kim Stanley Robinson | Head of the UN Ministry for the Future |
| Mary Doria Russell(M.D.R., the author) — The Sparrow | The Sparrow | Mary Doria Russell | narrator/author |
| Mary Kent(Lieutenant Kent, Mary) — Blackout/All Clear | Blackout/All Clear | Connie Willis | Oxford historian (undercover FANY) |
| Mary Noyes — The Demolished Man | The Demolished Man | Alfred Bester | Helper/unrequited lover |
| Maryalice — All Tomorrow's Parties | All Tomorrow's Parties | William Gibson | Bar patron |
| Maryalice — Idoru | Idoru | William Gibson | Smuggler |
| Marygay Potter(Marygay Potter-Mandella, Potter, 2LT Potter) — The Forever War | The Forever War | Joe Haldeman | primary romantic partner |
| Masahiko — Idoru | Idoru | William Gibson | Otaku and Walled City resident |
| Masao Yanoguchi(Dr. Yanoguchi) — The Sparrow | The Sparrow | Mary Doria Russell | ISAS Director / Arecibo administrator |
| Master Gyles — The Third Sally or The Dragons of Probability | The Third Sally or The Dragons of Probability | Stanislaw Lem | Trufflandrian native |
| Master Trevelyan — Stories of Your Life and Others | Stories of Your Life and Others | Ted Chiang | Teacher |
| Master Willoughby(Harold Willoughby) — Stories of Your Life and Others | Stories of Your Life and Others | Ted Chiang | Master Sculptor |
| Mateo(Pilar) — Adulthood Rites | Adulthood Rites | Octavia E. Butler | Resister |
| Matteo — Network Effect | Network Effect | Martha Wells | helper |
| Maurice Abramowicz — Three Versions of Judas | Three Versions of Judas | Jorge Luis Borges | Critic |
| Mavriva — The Left Hand of Darkness | The Left Hand of Darkness | Ursula K. Le Guin | helper |
| Max — Green Mars | Green Mars | Kim Stanley Robinson | Fellow seminar recruit |
| Max — Stars in My Pocket Like Grains of Sand | Stars in My Pocket Like Grains of Sand | Samuel R. Delany | Family Member/Host |
| Max — The Uplift War | The Uplift War | David Brin | actantial:helper |
| Maxime — Perhaps the Stars | Perhaps the Stars | Ada Palmer | Crewmate |
| Maxine Duval — The Fountains of Paradise | The Fountains of Paradise | Arthur C. Clarke | journalist / helper |
| Maxixe — The Fifth Season | The Fifth Season | N.K. Jemisin | Grit |
| Maxixe — The Stone Sky | The Stone Sky | N. K. Jemisin | Secondary character / foil to Essun |
| Maya(Maya Katarina Toitovna, Maya Toitovna, Ludmilla Novosibirskaya +3) — Blue Mars | Blue Mars | Kim Stanley Robinson | Russian contingent leader and central POV character |
| Maya(Bad Witch) — Green Mars | Green Mars | Kim Stanley Robinson | First Hundred revolutionary, political voice |
| Maya Toitovna(Ludmilla Novosibir-skaya) — Green Mars | Green Mars | Kim Stanley Robinson | POV protagonist; First Hundred revolutionary coordinator |
| Maya Toitovna(Maya, Maya Katarina Toitovna, The Black Widow +4) — Red Mars | Red Mars | Kim Stanley Robinson | Russian engineer, political and emotional center |
| Mayor Rudgutter(Rudgutter, Mayor, Mr. Mayor) — Perdido Street Station | Perdido Street Station | China Miéville | Mayor of New Crobuzon |
| Mbeke(Fiona) — Redshirts | Redshirts | John Scalzi | Expendable crewman |
| McDowell — Ancillary Sword | Ancillary Sword | Ann Leckie | captain |
| McFarland — The Gods Themselves | The Gods Themselves | Isaac Asimov | minor |
| McLuhan(hale and hearty old codger) — Sexplosion | Sexplosion | Stanislaw Lem | Philosopher |
| Media(Lucy, Lucy Ricardo) — American Gods | American Gods | Neil Gaiman | antagonist/new god |
| Medic — Ancillary Sword | Ancillary Sword | Ann Leckie | Ship's physician aboard Mercy of Kalr |
| Medic Norwood — Mirror Dance | Mirror Dance | Lois McMaster Bujold | absent pivot |
| Meina Gladstone(Senate CEO, CEO Gladstone, M. Executive) — Hyperion | Hyperion | Dan Simmons | CEO of the Hegemony Senate and All Thing |
| Meina Gladstone(CEO Gladstone, Gallstone, M. Executive +2) — The Fall of Hyperion | The Fall of Hyperion | Dan Simmons | CEO of the Hegemony; supreme political leader managing the war |
| Mel — Forever Peace | Forever Peace | Joe Haldeman | Platoon mechanic |
| Melania Housekeeper(Melania, housekeeper) — Klara and the Sun | Klara and the Sun | Kazuo Ishiguro | Housekeeper |
| Melio Arundez — Hyperion | Hyperion | Dan Simmons | Archaeologist/Rachel's former lover |
| Melio Arundez(Dr. Melio Arundez) — The Fall of Hyperion | The Fall of Hyperion | Dan Simmons | Archaeologist/helper |
| Melissa(Snake's daughter) — Dreamsnake | Dreamsnake | Vonda N. McIntyre | Adoptive daughter of Snake |
| Men in beige(first man in beige, tall one, short one +2) — Stars in My Pocket Like Grains of Sand | Stars in My Pocket Like Grains of Sand | Samuel R. Delany | Station Security / Workers |
| Mendel Shpilman(Mrs. Shpilman, Frank, Emanuel Lasker +2) — The Yiddish Policemen's Union | The Yiddish Policemen's Union | Michael Chabon | actantial sender/witness |
| Mendez(Father Mendez) — Forever Peace | Forever Peace | Joe Haldeman | helper |
| Menestius — The Will to Battle | The Will to Battle | Ada Palmer | Servicer |
| Mensah(Dr. Mensah, second mom) — Network Effect | Network Effect | Martha Wells | Preservation Council leader / Amena's mother |
| Mercer(Wilbur Mercer, Al Jarry) — Do Androids Dream of Electric Sheep? | Do Androids Dream of Electric Sheep? | Philip K. Dick | helper |
| Mercy of Kalr — Ancillary Justice | Ancillary Justice | Ann Leckie | helper |
| Mercy of Kalr(Ship) — Ancillary Sword | Ancillary Sword | Ann Leckie | AI ship |
| Mercy of Sarrse One Amaat One — Ancillary Justice | Ancillary Justice | Ann Leckie | actantial:helper |
| Merideth(Merry) — Dreamsnake | Dreamsnake | Vonda N. McIntyre | Jesse's partner |
| Merino(Ianni Merino) — Cyteen | Cyteen | C. J. Cherryh | Centrist political figure |
| MetaCop 1 — Snow Crash | Snow Crash | Neal Stephenson | opponent |
| MetaCop 2 — Snow Crash | Snow Crash | Neal Stephenson | opponent |
| Metz(Ignacio Metz, Doctor Metz, Dr. Metz) — Startide Rising | Startide Rising | David Brin | Human scientist / secret experimenter |
| Meyer Landsman(Landsman, Meyer, Naomi +1) — The Yiddish Policemen's Union | The Yiddish Policemen's Union | Michael Chabon | actantial helper (deceased) |
| Micah — The Uplift War | The Uplift War | David Brin | helper |
| Michael(Mike) — The Martian Chronicles | The Martian Chronicles | Ray Bradbury | Youngest son |
| Michael Chang(Chang) — Red Mars | Red Mars | Kim Stanley Robinson | minor |
| Michael Zacharias — Lost Futures | Lost Futures | Lisa Tuttle | Alternate-world husband / love interest |
| Michel(Michel Duval) — Blue Mars | Blue Mars | Kim Stanley Robinson | Colony psychiatrist and POV character |
| Michel(Michel Duval) — Red Mars | Red Mars | Kim Stanley Robinson | French psychiatrist to the First Hundred |
| Michel Duval — Green Mars | Green Mars | Kim Stanley Robinson | First Hundred psychologist; Maya's partner |
| Michelle — The Coral Bones | The Coral Bones | Jynne Martin | Telma's Committee boss |
| Micky Vayner — The Yiddish Policemen's Union | The Yiddish Policemen's Union | Michael Chabon | Minor |
| Microminians — The Seventh Sally or How Trurl's Own Perfection Led to No Good | The Seventh Sally or How Trurl's Own Perfection Led to No Good | Stanislaw Lem | collective agent |
| Midge — Never Let Me Go | Never Let Me Go | Kazuo Ishiguro | Hailsham student |
| Migliaccio — Starship Troopers | Starship Troopers | Robert A. Heinlein | first section leader / chaplain bearer |
| Miguel de Cervantes(Cervantes) — Pierre Menard, Author of the Quixote | Pierre Menard, Author of the Quixote | Jorge Luis Borges | opponent |
| Miguel de Cervantes(Cervantes, layman genius) — Rien du tout, ou la consequence | Rien du tout, ou la consequence | Stanislaw Lem | Author |
| Mihail — Network Effect | Network Effect | Martha Wells | Crew member / bridge officer |
| Mike(Mycroft Holmes, HOLMES FOUR, Michelle +4) — The Moon Is a Harsh Mistress | The Moon Is a Harsh Mistress | Robert A. Heinlein | Self-aware supercomputer managing Luna's infrastructure; revolutionary strategist |
| Mike Davies(Mike, Kansas, Michael Davies +1) — Blackout/All Clear | Blackout/All Clear | Connie Willis | Protagonist / stranded historian |
| Mike Donovan(Donovan, Mike) — I, Robot | I, Robot | Isaac Asimov | actantial:helper |
| Mike Takahashi(Mike, Takahashi) — Pushing Ice | Pushing Ice | Alastair Reynolds | EVA Worker |
| Mikhel Buric(Representative Buric, Minister Mikhel Buric) — The City & The City | The City & The City | China Miéville | Social Democrats politician |
| Mikyael Khurusch — The City & The City | The City & The City | China Miéville | Van owner |
| Milan — 2312 | 2312 | Kim Stanley Robinson | Head of Mercury House, New York |
| Miles(Lord Miles, the kid, boychick) — Barrayar | Barrayar | Lois McMaster Bujold | object/future subject |
| Milgrim — Spook Country | Spook Country | William Gibson | Captive Addict/Escapee |
| Milla(Ludmilla) — The Moon Is a Harsh Mistress | The Moon Is a Harsh Mistress | Robert A. Heinlein | Davis family member |
| Milo(Milo Silk) — Fledgling | Fledgling | Octavia E. Butler | Ina elder of the Silk family |
| Milton Ashe — I, Robot | I, Robot | Isaac Asimov | Assembly officer, U.S. Robots |
| Mima — Stars in My Pocket Like Grains of Sand | Stars in My Pocket Like Grains of Sand | Samuel R. Delany | Tour Guide / Retired med-tech2 |
| Minister Kraye(Casimir Perry, Merion Kraye, Thersites-Croucher-Perry-Kraye) — Perhaps the Stars | Perhaps the Stars | Ada Palmer | Mastermind |
| Minlu Moretti(Interim Minor Senator) — Perhaps the Stars | Perhaps the Stars | Ada Palmer | Laser hobbyist |
| Mir Bahadur Ali(Bahadur) — The Approach to Al-Mu'tasim | The Approach to Al-Mu'tasim | Jorge Luis Borges | Author |
| Miral Essos of Boeotia — Odysseus of Ithaca | Odysseus of Ithaca | Stanislaw Lem | Historical Genius |
| Miranda — The Diamond Age | The Diamond Age | Neal Stephenson | Ractor / surrogate mother |
| Miri Gu(Little General) — Rainbows End | Rainbows End | Vernor Vinge | Helper/Actant |
| Miriam — Stranger in a Strange Land | Stranger in a Strange Land | Robert A. Heinlein | Member of Harshaw's household |
| Miro — Speaker for the Dead | Speaker for the Dead | Orson Scott Card | Zenador apprentice, Novinha's eldest son |
| Misalem — The Fifth Season | The Fifth Season | N.K. Jemisin | Historical rogue orogene |
| Miss Braggs — The Calculating Stars | The Calculating Stars | Mary Robinette Kowal | supporting |
| Miss Braithwaite — The Diamond Age | The Diamond Age | Neal Stephenson | ractive character/actress |
| Miss Carroll(Alison Carroll, Alison) — Among Others | Among Others | Jo Walton | helper |
| Miss Coleman(Sarah) — The Calculating Stars | The Calculating Stars | Mary Robinette Kowal | supporting |
| Miss Eileen — Never Let Me Go | Never Let Me Go | Kazuo Ishiguro | Hailsham guardian |
| Miss Emily — Never Let Me Go | Never Let Me Go | Kazuo Ishiguro | Hailsham guardian or teacher |
| Miss Geraldine — Never Let Me Go | Never Let Me Go | Kazuo Ishiguro | Hailsham guardian |
| Miss Helen(Helen, Rick's mother) — Klara and the Sun | Klara and the Sun | Kazuo Ishiguro | Rick's mother |
| Miss Hibbard — Blackout/All Clear | Blackout/All Clear | Connie Willis | Shelter regular |
| Miss Laburnum — Blackout/All Clear | Blackout/All Clear | Connie Willis | Shelter regular |
| Miss Lucy — Never Let Me Go | Never Let Me Go | Kazuo Ishiguro | Former Hailsham Guardian |
| Miss Marsten(Ann Marsten, Ann) — Do Androids Dream of Electric Sheep? | Do Androids Dream of Electric Sheep? | Philip K. Dick | other |
| Miss Matheson — The Diamond Age | The Diamond Age | Neal Stephenson | Headmistress/philosopher |
| Miss Peaks — The Calculating Stars | The Calculating Stars | Mary Robinette Kowal | supporting |
| Miss Sharpe(Delphinium Sharpe) — To Say Nothing of the Dog | To Say Nothing of the Dog | Connie Willis | Cathedral Ladies' Altar Guild vice-chairwoman |
| Miss Snelgrove — Blackout/All Clear | Blackout/All Clear | Connie Willis | Supporting / floor supervisor |
| Miss Soo — Air | Air | Geoff Ryman | other |
| Miss Stricken — The Diamond Age | The Diamond Age | Neal Stephenson | Antagonist/teacher |
| Miss Ulrica Thrale — An Examination of the Work of Herbert Quain | An Examination of the Work of Herbert Quain | Jorge Luis Borges | Character in 'The Secret Mirror' |
| Miss Victoria MacTyre — The Separation | The Separation | Christopher Priest | helper |
| Mist — Dreamsnake | Dreamsnake | Vonda N. McIntyre | helper / instrument |
| Mistretl driver — Excession | Excession | Iain M. Banks | Driver |
| Mitchell — Count Zero | Count Zero | William Gibson | Defecting scientist |
| Mitsuko — Idoru | Idoru | William Gibson | Tokyo Lo/Rez chapter member |
| Mme Solange — A Perfect Vacuum | A Perfect Vacuum | Stanislaw Lem | Fictional Author |
| Mme. Henri Bachelier — Pierre Menard, Author of the Quixote | Pierre Menard, Author of the Quixote | Jorge Luis Borges | opponent |
| Moaning creature — Acceptance | Acceptance | Jeff VanderMeer | Mutated beast |
| Moddard — Solaris | Solaris | Stanislaw Lem | Crew member on the Prometheus |
| Mogul(Mogul Zodiac) — Take Back Plenty | Take Back Plenty | Colin Greenland | Zodiac Twin (male), acrobatic performer |
| Moira — The Handmaid's Tale | The Handmaid's Tale | Margaret Atwood | Offred's closest friend from before Gilead |
| Moki — Startide Rising | Startide Rising | David Brin | Neo-dolphin security patrol |
| Moklosich — The Sect of the Phoenix | The Sect of the Phoenix | Jorge Luis Borges | Scholar (refuted) |
| Mollen — Use of Weapons | Use of Weapons | Iain M. Banks | Servant / Enforcer |
| Molly — Lost Futures | Lost Futures | Lisa Tuttle | Non-existent child |
| Molly(street samurai, Cat Mother, Boston +2) — Neuromancer | Neuromancer | William Gibson | Augmented mercenary |
| Molly Wheelwright — Stranger in a Strange Land | Stranger in a Strange Land | Robert A. Heinlein | Minor character |
| Mom — Snow Crash | Snow Crash | Neal Stephenson | actantial:receiver |
| Mom(Alice) — The Martian Chronicles | The Martian Chronicles | Ray Bradbury | Mother |
| Mommadoll — Too Like the Lightning | Too Like the Lightning | Ada Palmer | Living toy doll |
| Mona — Mona Lisa Overdrive | Mona Lisa Overdrive | William Gibson | SINless teenager / prostitute |
| Mona Pierce — Forever Peace | Forever Peace | Joe Haldeman | supporting |
| Moneta(Mnemosyne) — Hyperion | Hyperion | Dan Simmons | Mysterious guide/anima figure |
| Monk Eastman(Eastman) — The Form of the Sword | The Form of the Sword | Jorge Luis Borges | Gangster / Ward Boss |
| Monkey-constructs(chimp-things, constructs) — Perdido Street Station | Perdido Street Station | China Miéville | Automated attack units |
| Monsignor Aurelio Colonna(Monsignor Colonna) — The Will to Battle | The Will to Battle | Ada Palmer | Vatican host |
| Monsignor Edouard — The Fall of Hyperion | The Fall of Hyperion | Dan Simmons | Jesuit cleric |
| Monsignor Flaught(advocatus diaboli, devil's advocate) — A Canticle for Leibowitz | A Canticle for Leibowitz | Walter M. Miller, Jr. | Opponent |
| Monsignor Malfreddo Aguerra(the postulator, Saint's advocate) — A Canticle for Leibowitz | A Canticle for Leibowitz | Walter M. Miller, Jr. | Sender/Helper |
| Montez — The Gods Themselves | The Gods Themselves | Isaac Asimov | Outgoing Earth Commissioner |
| Montjohn Rescue(Rescue, Rescue-handlinger) — Perdido Street Station | Perdido Street Station | China Miéville | Mayor's vizier and Handlinger |
| Montoya — Doomsday Book | Doomsday Book | Connie Willis | Oxford archaeologist; helper |
| Moon Dawntreader Summer(Moon, sibyl, Summer Queen +1) — The Snow Queen | The Snow Queen | Joan D. Vinge | Protagonist, sibyl, future Summer Queen |
| Moore — Stories of Your Life and Others | Stories of Your Life and Others | Ted Chiang | Journeyman sculptor |
| Moore(Captain Moore) — The Forever War | The Forever War | Joe Haldeman | Executive officer/staff |
| Mor — Among Others | Among Others | Jo Walton | deceased twin / actantial object |
| Morgan — Lord of Light | Lord of Light | Roger Zelazny | minor |
| Morrow — Anxiety Is the Dizziness of Freedom | Anxiety Is the Dizziness of Freedom | Ted Chiang | Owner of SelfTalk, Scammer |
| Morrow — Exhalation | Exhalation | Ted Chiang | Store Manager / Scammer |
| Mors Planch — The Foundation Trilogy | The Foundation Trilogy | Isaac Asimov | free-trader engineer / reluctant witness |
| Morwenna Phelps(Mori, Morwenna Markova, Hopalong +6) — Among Others | Among Others | Jo Walton | protagonist-narrator |
| Moseby — Exhalation | Exhalation | Ted Chiang | Missionary |
| Moseby — The Truth of Fact, the Truth of Feeling | The Truth of Fact, the Truth of Feeling | Ted Chiang | European Missionary |
| Mother(Liz, Mama) — Among Others | Among Others | Jo Walton | opponent / antagonist |
| Mother(The Voice) — Authority | Authority | Jeff VanderMeer | Control's superior at Central |
| Mother(Mom) — Nova | Nova | Samuel R. Delany | Lorq's mother |
| Mr Atakoloo — Air | Air | Geoff Ryman | other |
| Mr Capaldi(Henry, Mr Son Bitch, Portrait guy) — Klara and the Sun | Klara and the Sun | Kazuo Ishiguro | Scientist/Artist |
| Mr Ken(Ken Kuei, Kuei) — Air | Air | Geoff Ryman | Love interest |
| Mr Mack(Musa Mack) — Air | Air | Geoff Ryman | secondary |
| Mr Oz(the Central Man, Central Bureau of Information Technology man, Central Man +1) — Air | Air | Geoff Ryman | Government operative / helper |
| Mr Pakan(Mr Real Man) — Air | Air | Geoff Ryman | opponent |
| Mr Tunch(Hikmet Tunch, Wisdom Bronze, Bronze +4) — Air | Air | Geoff Ryman | secondary |
| Mr Vance(Vance) — Klara and the Sun | Klara and the Sun | Kazuo Ishiguro | Miss Helen's former partner |
| Mr Wing(Wing) — Air | Air | Geoff Ryman | Village figure / host |
| Mr. Beck — The Diamond Age | The Diamond Age | Neal Stephenson | Technical boy/ally |
| Mr. Cecil Roberts — The Approach to Al-Mu'tasim | The Approach to Al-Mu'tasim | Jorge Luis Borges | Critic |
| Mr. Charrington(the old man) — 1984 | 1984 | George Orwell | apparent helper |
| Mr. Chiswick — To Say Nothing of the Dog | To Say Nothing of the Dog | Connie Willis | Exposition/opponent |
| Mr. Dahl — Omphalos | Omphalos | Ted Chiang | Gift shop salesman |
| Mr. Dorming — Blackout/All Clear | Blackout/All Clear | Connie Willis | Shelter regular |
| Mr. Dubois(Colonel Dubois) — Starship Troopers | Starship Troopers | Robert A. Heinlein | History and Moral Philosophy teacher / actantial sender |
| Mr. Dunworthy — Blackout/All Clear | Blackout/All Clear | Connie Willis | Oxford authority figure |
| Mr. Dunworthy — To Say Nothing of the Dog | To Say Nothing of the Dog | Connie Willis | Sender/authority |
| Mr. Golde — Childhood's End | Childhood's End | Arthur C. Clarke | press figure |
| Mr. Hexter — New York 2140 | New York 2140 | Kim Stanley Robinson | Archivist |
| Mr. Ibis(Ibis) — American Gods | American Gods | Neil Gaiman | helper/old god |
| Mr. Jones — A Perfect Vacuum | A Perfect Vacuum | Stanislaw Lem | Fictional Client |
| Mr. Jones — Being Inc. | Being Inc. | Stanislaw Lem | Hypothetical Client |
| Mr. K(Yll) — The Martian Chronicles | The Martian Chronicles | Ray Bradbury | Antagonist / Ylla's husband |
| Mr. Kimball — The Coral Bones | The Coral Bones | Jynne Martin | Botanist |
| Mr. Lee — Snow Crash | Snow Crash | Neal Stephenson | helper |
| Mr. Motley(Motley) — Perdido Street Station | Perdido Street Station | China Miéville | Crime boss / Patron |
| Mr. Nancy(Anansi, Nancy) — American Gods | American Gods | Neil Gaiman | Helper / trickster |
| Mr. Oda — The Diamond Age | The Diamond Age | Neal Stephenson | Ally/acquaintance |
| Mr. Rush — The Coral Bones | The Coral Bones | Jynne Martin | Ship's officer/draughtsman |
| Mr. Simms — Blackout/All Clear | Blackout/All Clear | Connie Willis | Shelter regular |
| Mr. Smith(Smith) — A Perfect Vacuum | A Perfect Vacuum | Stanislaw Lem | Fictional Client |
| Mr. Smith(Smith) — Being Inc. | Being Inc. | Stanislaw Lem | Hypothetical Client |
| Mr. Spivens — To Say Nothing of the Dog | To Say Nothing of the Dog | Connie Willis | Minor/comic |
| Mr. Struthers — I, Robot | I, Robot | Isaac Asimov | actantial:helper |
| Mr. Town(Town, Mack) — American Gods | American Gods | Neil Gaiman | actantial:opponent |
| Mr. Tucker — The Coral Bones | The Coral Bones | Jynne Martin | Botanist |
| Mr. William Stendahl(Stendahl) — The Martian Chronicles | The Martian Chronicles | Ray Bradbury | protagonist |
| Mr. Xxx — The Martian Chronicles | The Martian Chronicles | Ray Bradbury | Martian psychologist / bureaucratic opponent |
| Mrs Tung(Granny Tung, Old Mrs Tung, Granny +3) — Air | Air | Geoff Ryman | Deceased elder / internal presence |
| Mrs. Bascombe — Blackout/All Clear | Blackout/All Clear | Connie Willis | minor |
| Mrs. Bittner(Lizzie, Liz, Lizzie Bittner) — To Say Nothing of the Dog | To Say Nothing of the Dog | Connie Willis | Historical figure encountered in time-slip |
| Mrs. Brightford — Blackout/All Clear | Blackout/All Clear | Connie Willis | Shelter regular |
| Mrs. Brown — A Perfect Vacuum | A Perfect Vacuum | Stanislaw Lem | Fictional Target |
| Mrs. Brown — Being Inc. | Being Inc. | Stanislaw Lem | Hypothetical Victim |
| Mrs. Gaddson — Doomsday Book | Doomsday Book | Connie Willis | Comic obstacle; quarantine intruder |
| Mrs. Godwin — Dacey's Patent Automatic Nanny | Dacey's Patent Automatic Nanny | Ted Chiang | Customer |
| Mrs. Grace Weston(Mamma) — I, Robot | I, Robot | Isaac Asimov | actantial:opponent |
| Mrs. Grales(Old Ma'am Grales, Rachel) — A Canticle for Leibowitz | A Canticle for Leibowitz | Walter M. Miller, Jr. | actantial:helper |
| Mrs. Hastings — Dacey's Patent Automatic Nanny | Dacey's Patent Automatic Nanny | Ted Chiang | Customer |
| Mrs. Jessamine Chest(Jessamine Chest) — Being Inc. | Being Inc. | Stanislaw Lem | Client |
| Mrs. Kare — The Calculating Stars | The Calculating Stars | Mary Robinette Kowal | minor |
| Mrs. Lebourgeois(Violette Lebourgeois) — The Calculating Stars | The Calculating Stars | Mary Robinette Kowal | helper |
| Mrs. Lindholm — The Calculating Stars | The Calculating Stars | Mary Robinette Kowal | helper |
| Mrs. Marmalade(Miss Marmalade) — To Say Nothing of the Dog | To Say Nothing of the Dog | Connie Willis | Minor character/comic device |
| Mrs. Menhenick — Dacey's Patent Automatic Nanny | Dacey's Patent Automatic Nanny | Ted Chiang | Customer |
| Mrs. Rickett — Blackout/All Clear | Blackout/All Clear | Connie Willis | antagonist |
| Mrs. Rivas — Division by Zero | Division by Zero | Ted Chiang | Psychiatric ward patient |
| Mrs. Rivas — Stories of Your Life and Others | Stories of Your Life and Others | Ted Chiang | Patient |
| Mrs. Rogers — The Calculating Stars | The Calculating Stars | Mary Robinette Kowal | minor |
| Mrs. Sadler — Blackout/All Clear | Blackout/All Clear | Connie Willis | minor |
| Ms. Chumlig(Chumlig) — Rainbows End | Rainbows End | Vernor Vinge | actantial:opponent |
| Ms. Cooper — Virtual Light | Virtual Light | William Gibson | IntenSecure client |
| Multitudians — Tale of the Three Storytelling Machines of King Genius | Tale of the Three Storytelling Machines of King Genius | Stanislaw Lem | Populous Race |
| Mum(Mimi Davis, Cassie) — The Moon Is a Harsh Mistress | The Moon Is a Harsh Mistress | Robert A. Heinlein | Mannie's senior wife and family matriarch |
| Munn Li Compor(Compor) — Foundation's Edge | Foundation's Edge | Isaac Asimov | Foundation agent / Second Foundation informant |
| Muntius — Solaris | Solaris | Stanislaw Lem | Author and Solarist critic |
| Murderbot 2.0(2.0, killware, other me) — Network Effect | Network Effect | Martha Wells | helper |
| Murga — Lord of Light | Lord of Light | Roger Zelazny | minor |
| Murugan(youthgod) — Lord of Light | Lord of Light | Roger Zelazny | minor |
| My Owner(His Holiness, Your Holiness) — Seven Surrenders | Seven Surrenders | Ada Palmer | Captor / Patron of Sniper |
| Mycroft Canner(Mycroft, tired guide, mad historian +11) — Perhaps the Stars | Perhaps the Stars | Ada Palmer | Narrative protagonist and conversational pivot |
| Mycroft Canner(Saladin, The Monster, Slave Mycroft +6) — Seven Surrenders | Seven Surrenders | Ada Palmer | Narrator and protector of Bridger |
| Mycroft Canner(Mycroft, I, cannibal) — The Will to Battle | The Will to Battle | Ada Palmer | Narrator, captive, messenger |
| Mycroft Canner(Mycroft, Servicer, monster +3) — Too Like the Lightning | Too Like the Lightning | Ada Palmer | Convict/Servicer and primary narrator |
| Mycroft's successor — Perhaps the Stars | Perhaps the Stars | Ada Palmer | Analyst and captive leader |
| Mymosh(Mymosh the Selfbegotten) — The Cyberiad | The Cyberiad | Stanislaw Lem | Creator entity |
| Mymosh the Selfbegotten(Mymosh) — Tale of the Three Storytelling Machines of King Genius | Tale of the Three Storytelling Machines of King Genius | Stanislaw Lem | Accidental Entity |
| Myron(Herr Doctor Professor Sergeant Myron) — Rendezvous with Rama | Rendezvous with Rama | Arthur C. Clarke | Crew member |
| Myron Bronowski(Mike) — The Gods Themselves | The Gods Themselves | Isaac Asimov | helper |
| Myrtle — The Calculating Stars | The Calculating Stars | Mary Robinette Kowal | supporting |
| Mysterious Voice — All Tomorrow's Parties | All Tomorrow's Parties | William Gibson | Employer / Observer |
| Mystery — Hyperion | Hyperion | Dan Simmons | Mysterious recurring figure |
| N. Kiddy(Enkidu, Judas) — Gigamesh | Gigamesh | Stanislaw Lem | Antagonist of Gigamesh |
| NAAD — Non Serviam | Non Serviam | Stanislaw Lem | Personoid interlocutor |
| Nadia(Nadezhda Cherneshevsky, Nadia Chernevsky, Nadia Cherneshevsky) — Blue Mars | Blue Mars | Kim Stanley Robinson | Engineer and revolutionary coordinator |
| Nadia(General Nadia, designated arbitrator, universal solvent) — Green Mars | Green Mars | Kim Stanley Robinson | Engineer, revolutionary coordinator, First Hundred |
| Nadia(Nadezhda Francine, Ms. Nine Fingers, Nadezhda +3) — Red Mars | Red Mars | Kim Stanley Robinson | Engineer, pragmatic problem-solver, reluctant mediator |
| Nadir Devanbegi(effendi) — The Years of Rice and Salt | The Years of Rice and Salt | Kim Stanley Robinson | Khan's treasurer and political overseer |
| Naga Chief(the burly leader of the Nagas) — Lord of Light | Lord of Light | Roger Zelazny | minor opponent |
| Naidi — Starship Troopers | Starship Troopers | Robert A. Heinlein | minor character |
| Najya — The Merchant and the Alchemist's Gate | The Merchant and the Alchemist's Gate | Ted Chiang | Fuwaad's deceased wife |
| Namarath Godhisavatta(Head, Head of Customs) — Foundation's Edge | Foundation's Edge | Isaac Asimov | Head of Customs, Dreamer |
| Nanao Nakayama — Red Mars | Red Mars | Kim Stanley Robinson | Issei Sabishiian host |
| Nanni — Tower of Babylon | Tower of Babylon | Ted Chiang | Elamite miner |
| Nanny Gibson — Dacey's Patent Automatic Nanny | Dacey's Patent Automatic Nanny | Ted Chiang | Human nanny |
| Naomi Nagata — Ancillary Sword | Ancillary Sword | Ann Leckie | chief engineer |
| Napoerea — Use of Weapons | Use of Weapons | Iain M. Banks | High Priest / Leader |
| Narodny Mars Vice-President(the Martian banker, the man in the wheelchair) — The Fountains of Paradise | The Fountains of Paradise | Arthur C. Clarke | Actantial sender / Financier |
| Narong — The Windup Girl | The Windup Girl | Paolo Bacigalupi | Trade Ministry operative |
| Narrator — A Perfect Vacuum | A Perfect Vacuum | Stanislaw Lem | Lecturer / Theorist |
| Narrator — The Truth of Fact, the Truth of Feeling | The Truth of Fact, the Truth of Feeling | Ted Chiang | Journalist and Father |
| Narrator(tribune) — Tlön, Uqbar, Orbis Tertius | Tlön, Uqbar, Orbis Tertius | Jorge Luis Borges | Roman military tribune |
| Narrator (Book of Sand) — Tlön, Uqbar, Orbis Tertius | Tlön, Uqbar, Orbis Tertius | Jorge Luis Borges | Collector/Misanthrope |
| Narrator (Remem User)(Puerto Rican Parrot) — Exhalation | Exhalation | Ted Chiang | Narrator and father |
| Narrator of Blue Tigers — The Form of the Sword | The Form of the Sword | Jorge Luis Borges | Investigator / Professor |
| Naser Shah(Naser, the old one-armed soldier) — The Years of Rice and Salt | The Years of Rice and Salt | Kim Stanley Robinson | Interlocutor, veteran |
| Nasir Harad(Chairman Harad) — Cyteen | Cyteen | C. J. Cherryh | bureaucracy/actantial:opponent |
| Nassun — The Stone Sky | The Stone Sky | N. K. Jemisin | Essun's daughter / Secondary protagonist |
| Nat — Anxiety Is the Dizziness of Freedom | Anxiety Is the Dizziness of Freedom | Ted Chiang | Employee at SelfTalk, Undercover Support Group Member |
| Nat — Exhalation | Exhalation | Ted Chiang | Protagonist / Store Employee / Conspirator |
| Natal — Imago | Imago | Octavia E. Butler | Human resister |
| Natekari(Tribune Natekari, Blacklaw Tribune) — The Will to Battle | The Will to Battle | Ada Palmer | Blacklaw Tribune |
| Nathanael — Hell Is the Absence of God | Hell Is the Absence of God | Ted Chiang | Angel |
| Nathanael — Stories of Your Life and Others | Stories of Your Life and Others | Ted Chiang | Angel |
| Nathaniel York(Dr. York, Elma Wexler, Mrs. York +4) — The Calculating Stars | The Calculating Stars | Mary Robinette Kowal | protagonist |
| Navio(Dom Navio, Enrique o Navigador Caronada) — Speaker for the Dead | Speaker for the Dead | Orson Scott Card | Opponent |
| Nazik — Blue Mars | Blue Mars | Kim Stanley Robinson | Zeyk's partner |
| Nazik — Green Mars | Green Mars | Kim Stanley Robinson | Zeyk's wife; Arab Martian underground member |
| Nazik — Red Mars | Red Mars | Kim Stanley Robinson | Zeyk's wife, witness |
| Nea Thant(George, Nea) — Stars in My Pocket Like Grains of Sand | Stars in My Pocket Like Grains of Sand | Samuel R. Delany | Antagonist / Sister |
| Neci — Imago | Imago | Octavia E. Butler | Resister |
| Neci Roybal(Stancio, Neci) — Adulthood Rites | Adulthood Rites | Octavia E. Butler | Extremist resister |
| Ned Henry(Lieutenant Ned Henry, John Bartholomew, Mr. Henry +1) — To Say Nothing of the Dog | To Say Nothing of the Dog | Connie Willis | Protagonist/narrator |
| Nefud — Dune | Dune | Frank Herbert | actantial:helper |
| Negri — Barrayar | Barrayar | Lois McMaster Bujold | actantial helper/donor |
| Neil Fisk — Hell Is the Absence of God | Hell Is the Absence of God | Ted Chiang | Neil's wife |
| Neil Fisk(Sarah, Neil) — Stories of Your Life and Others | Stories of Your Life and Others | Ted Chiang | Protagonist / Grieving husband |
| Neinte(princess) — Use of Weapons | Use of Weapons | Iain M. Banks | Princess |
| Nell(Princess Nell, Queen Nell) — The Diamond Age | The Diamond Age | Neal Stephenson | Primer protagonist (embedded narrative) |
| Nelly — Cyteen | Cyteen | C. J. Cherryh | helper |
| Nelson — Story of Your Life | Story of Your Life | Ted Chiang | Future Partner |
| Nessus — Ringworld | Ringworld | Larry Niven | absent helper/trickster |
| Nestor 10(NS-10) — I, Robot | I, Robot | Isaac Asimov | Modified robot, antagonist |
| Neville(Barron, Barren, Barron Neville +3) — The Gods Themselves | The Gods Themselves | Isaac Asimov | Lunarite physicist; Selene's partner; antagonist of Part 3 |
| New recruit(Egbert) — To Say Nothing of the Dog | To Say Nothing of the Dog | Connie Willis | Minor/comic |
| Ng(Mr. Ng) — Snow Crash | Snow Crash | Neal Stephenson | helper |
| Ngemi — Pattern Recognition | Pattern Recognition | William Gibson | Collector |
| Ngenet(Miroe Ngenet, Citizen Ngenet, Miroe) — The Snow Queen | The Snow Queen | Joan D. Vinge | Plantation owner, Jerusha's companion |
| Nicholas Ashbourne(Ashbourne, Dr. Ashbourne, the elder nomenclator) — Seventy-Two Letters | Seventy-Two Letters | Ted Chiang | Nomenclator |
| Nicholas Russell — Queen of the States | Queen of the States | Lisa Goldstein | Opponent (conspirator) |
| Nick — The Handmaid's Tale | The Handmaid's Tale | Margaret Atwood | Commander's chauffeur and Guardian |
| Nick Weinstein(Anon-a-Writer) — Redshirts | Redshirts | John Scalzi | Head writer of Chronicles of the Intrepid |
| Nicole — Exhalation | Exhalation | Ted Chiang | Daughter |
| Nicole — The Truth of Fact, the Truth of Feeling | The Truth of Fact, the Truth of Feeling | Ted Chiang | Narrator's Daughter |
| Nicole Wargin — The Calculating Stars | The Calculating Stars | Mary Robinette Kowal | supporting |
| Nigel — Virtual Light | Virtual Light | William Gibson | Mechanic on the bridge |
| Nigel Hawthorne — Dacey's Patent Automatic Nanny | Dacey's Patent Automatic Nanny | Ted Chiang | Infant |
| Nikanj(Nika, Chkah) — Adulthood Rites | Adulthood Rites | Octavia E. Butler | Oankali ooloi |
| Nikanj — Dawn | Dawn | Octavia E. Butler | Ooloi mated to Lilith and Joseph |
| Nikanj(Kaalnikanj oo Jdahyatediinkahguyaht aj Dinso, Kaalnikanjl oo Jdahyatediinkahguyaht aj Dinso, Nika +3) — Imago | Imago | Octavia E. Butler | Ooloi parent to Jodahs and Aaor |
| Nils Runeberg — Three Versions of Judas | Three Versions of Judas | Jorge Luis Borges | Theologian and Protagonist |
| Nils Runeberg — Tlön, Uqbar, Orbis Tertius | Tlön, Uqbar, Orbis Tertius | Jorge Luis Borges | Theologian/Author |
| Nine Arch — A Desolation Called Peace | A Desolation Called Peace | Arkady Martine | minor |
| Nine Hibiscus(yaotlek, Mallow) — A Desolation Called Peace | A Desolation Called Peace | Arkady Martine | Yaotlek (fleet commander), Fleet Captain of the Tenth Legion |
| Nineteen Adze(the Emperor, Her Illuminate Majesty) — A Desolation Called Peace | A Desolation Called Peace | Arkady Martine | Reigning Emperor |
| Ninth Anonymous — The Will to Battle | The Will to Battle | Ada Palmer | Narrator and successor to Mycroft |
| Nirgal — Blue Mars | Blue Mars | Kim Stanley Robinson | Second-generation Martian protagonist |
| Nirgal(Uncle Nirgie) — Green Mars | Green Mars | Kim Stanley Robinson | Native-born Martian / emerging revolutionary figure |
| Nirgal — Red Mars | Red Mars | Kim Stanley Robinson | Second-generation Martian, political emissary |
| Nirriti(the Black One, Renfrew) — Lord of Light | Lord of Light | Roger Zelazny | opponent |
| Niss(Niss machine, Tymbrimi Niss machine) — Startide Rising | Startide Rising | David Brin | Tymbrimi intelligence device / actantial helper |
| Nita — The Uplift War | The Uplift War | David Brin | Minor character / neo-chimpanzee |
| No Fixed Abode — Excession | Excession | Iain M. Banks | Ship Mind |
| Node maintainer — The Fifth Season | The Fifth Season | N.K. Jemisin | Murdered child / living tool |
| Nora — Pattern Recognition | Pattern Recognition | William Gibson | The Maker |
| Nora Erfjord — The Circular Ruins | The Circular Ruins | Jorge Luis Borges | Secretary |
| Nora Erfjord — The Form of the Sword | The Form of the Sword | Jorge Luis Borges | Congress member |
| Nora Reuben — Stand on Zanzibar | Stand on Zanzibar | John Brunner | GT senior VP, electronics and communications |
| Norbert Wiener — Non Serviam | Non Serviam | Stanislaw Lem | Referenced progenitor |
| Norio Ituno — Gateway | Gateway | Frederik Pohl | actantial:helper |
| Norman House(Norman, Mr. House, Dr. Norman Niblock House) — Stand on Zanzibar | Stand on Zanzibar | John Brunner | Protagonist / corporate executive |
| North — Dreamsnake | Dreamsnake | Vonda N. McIntyre | Antagonist |
| Not Invented Here — Excession | Excession | Iain M. Banks | Medium Systems Vehicle |
| Novinha(Ivanova) — Speaker for the Dead | Speaker for the Dead | Orson Scott Card | Xenobiologist, central figure of mystery |
| Nunyunnini — American Gods | American Gods | Neil Gaiman | deity |
| Nurse Trisha(Crow Face) — Never Let Me Go | Never Let Me Go | Kazuo Ishiguro | Nurse |
| Nyberg — Starship Troopers | Starship Troopers | Robert A. Heinlein | minor |
| O'Brien — 1984 | 1984 | George Orwell | apparent helper/antagonist |
| O'Connor — Funes the Memorious | Funes the Memorious | Jorge Luis Borges | Doctor |
| Obomi(Zad, Zadkiel Obomi, President Obomi) — Stand on Zanzibar | Stand on Zanzibar | John Brunner | President of Beninia |
| Obsle — The Left Hand of Darkness | The Left Hand of Darkness | Ursula K. Le Guin | Commensal politician |
| Ockham Prospero Saneer(Prospero, Lesley) — Perhaps the Stars | Perhaps the Stars | Ada Palmer | Leader of O.S. / Romanova Security |
| Ockham Prospero Saneer(Prospero, O.S.) — The Will to Battle | The Will to Battle | Ada Palmer | O.S. leader / defendant |
| Ockham Saneer(Lesley, Lesley Juniper, Thiz +2) — Seven Surrenders | Seven Surrenders | Ada Palmer | Security / Member of Saneer-Weeksbooth |
| Odeen(left-dear) — The Gods Themselves | The Gods Themselves | Isaac Asimov | Rational triad member; protagonist of Part 2 |
| Odile Richard(Odile) — Spook Country | Spook Country | William Gibson | Art curator |
| Offred — The Handmaid's Tale | The Handmaid's Tale | Margaret Atwood | Narrator and protagonist, Handmaid |
| Ofglen — The Handmaid's Tale | The Handmaid's Tale | Margaret Atwood | Handmaid, shopping partner, Mayday operative |
| Oían(poet) — Tlön, Uqbar, Orbis Tertius | Tlön, Uqbar, Orbis Tertius | Jorge Luis Borges | King's poet |
| Oishi Kuranosuké(the councilor) — The Form of the Sword | The Form of the Sword | Jorge Luis Borges | Leader of the avenging Rônins |
| Ojiro Cardigan Sniper(Ojiro, Cardie, Cardigan +4) — Seven Surrenders | Seven Surrenders | Ada Palmer | Licensed sensayer, athlete, and fugitive |
| Ojo — Ammonite | Ammonite | Nicola Griffith | Briogannon leader |
| Okakura — Blue Mars | Blue Mars | Kim Stanley Robinson | Industrial settlement manager |
| Okakura — Red Mars | Red Mars | Kim Stanley Robinson | local official at Senzeni Na |
| Old Fried Eggs — Les Robinsonades | Les Robinsonades | Stanislaw Lem | Imaginary Relative |
| old gaucho(motionless old gaucho) — The South | The South | Jorge Luis Borges | symbolic helper |
| Old GT(GT, Georgette Tallon Buckfast) — Stand on Zanzibar | Stand on Zanzibar | John Brunner | corporate matriarch |
| Old Hunter — Stars in My Pocket Like Grains of Sand | Stars in My Pocket Like Grains of Sand | Samuel R. Delany | Hunter |
| Old Man (gas station)(Pop) — The Martian Chronicles | The Martian Chronicles | Ray Bradbury | helper |
| Old Mrs Ken — Air | Air | Geoff Ryman | helper |
| Old Mrs Wang(Mama) — Air | Air | Geoff Ryman | Mae's mother |
| Old One — A Fire Upon the Deep | A Fire Upon the Deep | Vernor Vinge | sender/trickster |
| Oldham — Stand on Zanzibar | Stand on Zanzibar | John Brunner | military officer |
| Olhado — Speaker for the Dead | Speaker for the Dead | Orson Scott Card | Novinha's son, Ender's computer assistant |
| Oliver Sleight(Ollie) — Spook Country | Spook Country | William Gibson | Blue Ant representative |
| Olivia Lagdameo(Olivia) — The Yiddish Policemen's Union | The Yiddish Policemen's Union | Michael Chabon | minor character |
| Ollie — Cyteen | Cyteen | C. J. Cherryh | helper |
| Ollivet't Doru(Ollivet't, Skalla Ollivet't, Shalleme +1) — Stars in My Pocket Like Grains of Sand | Stars in My Pocket Like Grains of Sand | Samuel R. Delany | Hunter |
| Olvagga(Jan Olvegg, Olvegg) — Lord of Light | Lord of Light | Roger Zelazny | helper/opponent |
| Ong Tot Oppong(Otie Nim) — The Left Hand of Darkness | The Left Hand of Darkness | Ursula K. Le Guin | Ekumenical Investigator / embedded narrator |
| Oouoh — A Closed and Common Orbit | A Closed and Common Orbit | Becky Chambers | minor crew |
| Orlovsky — Virtual Light | Virtual Light | William Gibson | Homicide Cop / Enforcer |
| Ornella — Anxiety Is the Dizziness of Freedom | Anxiety Is the Dizziness of Freedom | Ted Chiang | Personal Assistant |
| Ornella — Exhalation | Exhalation | Ted Chiang | Personal Assistant |
| Orton — Tlön, Uqbar, Orbis Tertius | Tlön, Uqbar, Orbis Tertius | Jorge Luis Borges | Impostor |
| Ossian(Mr. Murphy) — The Peripheral | The Peripheral | William Gibson | Technical operator |
| Otorhinolaryngologist — De Impossibilitate Vitae / De Impossibilitate Prognoscendi | De Impossibilitate Vitae / De Impossibilitate Prognoscendi | Stanislaw Lem | Doctor |
| Otto — The Windup Girl | The Windup Girl | Paolo Bacigalupi | Minor farang businessman |
| Otto Dietrich zur Linde — The Form of the Sword | The Form of the Sword | Jorge Luis Borges | Nazi officer/Condemned man |
| Otto Dietrich zur Linde(zur Linde) — Tlön, Uqbar, Orbis Tertius | Tlön, Uqbar, Orbis Tertius | Jorge Luis Borges | Torturer |
| Ouanda — Speaker for the Dead | Speaker for the Dead | Orson Scott Card | Co-Zenador, Miro's partner |
| Overse — Network Effect | Network Effect | Martha Wells | Survey crew member / Arada's marital partner |
| Owen — Among Others | Among Others | Jo Walton | minor |
| Owl — A Closed and Common Orbit | A Closed and Common Orbit | Becky Chambers | helper/mentor |
| Oyamar — The Fifth Season | The Fifth Season | N.K. Jemisin | Comm Member |
| Oyarzabal — The Snow Queen | The Snow Queen | Joan D. Vinge | Antagonist's instrument, Tor's fiancé |
| Pagel(Brigadier General Pagel) — Forever Peace | Forever Peace | Joe Haldeman | other |
| Pahkerr — A Closed and Common Orbit | A Closed and Common Orbit | Becky Chambers | minor AI |
| Pai — The Windup Girl | The Windup Girl | Paolo Bacigalupi | Environment Ministry officer |
| Paige — Blackout/All Clear | Blackout/All Clear | Connie Willis | Contemp companion |
| Palat — The Dispossessed | The Dispossessed | Ursula K. Le Guin | Shevek's father |
| Paleopithecanthropus — De Impossibilitate Vitae / De Impossibilitate Prognoscendi | De Impossibilitate Vitae / De Impossibilitate Prognoscendi | Stanislaw Lem | Protohuman ancestor |
| Pamela Mainwaring(Pamela) — Pattern Recognition | Pattern Recognition | William Gibson | Blue Ant employee |
| Pamela Mainwaring(Pamela) — Spook Country | Spook Country | William Gibson | Blue Ant fixer/coordinator |
| Pao — The Years of Rice and Salt | The Years of Rice and Salt | Kim Stanley Robinson | Companion to Kang |
| Papadelias(Papa, Commissioner General) — Seven Surrenders | Seven Surrenders | Ada Palmer | Police Commissioner General |
| Papadelias(Papa, Commissioner General) — The Will to Battle | The Will to Battle | Ada Palmer | Police Commissioner |
| Papadelias(Commissioner General) — Too Like the Lightning | Too Like the Lightning | Ada Palmer | Commissioner General |
| Papagaster(Prime Minister, My Lord Papagaster of the great house of Pentaperihelion) — The Fifth Sally or The Mischief of King Balerion | The Fifth Sally or The Mischief of King Balerion | Stanislaw Lem | Prime Minister |
| Paracelsus(the master) — The Form of the Sword | The Form of the Sword | Jorge Luis Borges | Alchemist / Master |
| Pardot Kynes(First Planetologist of Arrakis) — Dune | Dune | Frank Herbert | exposition figure |
| Park — Forever Peace | Forever Peace | Joe Haldeman | foil |
| Parkaboy(Peter Gilbert, Thornton Vaseltarp, Gilbert) — Pattern Recognition | Pattern Recognition | William Gibson | Online footagehead and collaborator |
| Parrish(Jitters) — Blackout/All Clear | Blackout/All Clear | Connie Willis | FANY unit member |
| Parry Boyce(Parry, Chief) — Pushing Ice | Pushing Ice | Alastair Reynolds | EVA Team Leader |
| Parsons — 1984 | 1984 | George Orwell | secondary character |
| Pascale — Revelation Space | Revelation Space | Alastair Reynolds | Biographer |
| Pat Garrett — The Circular Ruins | The Circular Ruins | Jorge Luis Borges | Sheriff |
| Patriarch(old sage, snow-white patriarch) — Tale of the Three Storytelling Machines of King Genius | Tale of the Three Storytelling Machines of King Genius | Stanislaw Lem | Simulated Sage |
| Patrick(Brother Pat) — A Canticle for Leibowitz | A Canticle for Leibowitz | Walter M. Miller, Jr. | minor |
| Patrick Hannahan — A Perfect Vacuum | A Perfect Vacuum | Stanislaw Lem | Fictional Author |
| Patrick Hannahan — Gigamesh | Gigamesh | Stanislaw Lem | Author |
| Patrick Matheson — The Separation | The Separation | Christopher Priest | Tribunal chairman |
| Patrick Westin — Rainbows End | Rainbows End | Vernor Vinge | Military subordinate |
| Patty Paiwonski(Patty, Aunt Patty, Pat +1) — Stranger in a Strange Land | Stranger in a Strange Land | Robert A. Heinlein | actantial:helper |
| Paul — Cyteen | Cyteen | C. J. Cherryh | Jordan Warrick's azi companion |
| Paul(Paul Atreides, Muad'Dib, Kwisatz Haderach +8) — Dune | Dune | Frank Herbert | Protagonist; messianic figure |
| Paul — Lost Futures | Lost Futures | Lisa Tuttle | one-night stand |
| Paul Hogg(Hogg) — Queen of the States | Queen of the States | Lisa Goldstein | Alchemist antagonist |
| Paul Kelly — Tlön, Uqbar, Orbis Tertius | Tlön, Uqbar, Orbis Tertius | Jorge Luis Borges | Gang leader |
| Paul Sarath(Professor Sarath) — The Fountains of Paradise | The Fountains of Paradise | Arthur C. Clarke | Minor supporting character |
| Paul Titus(Titus) — Imago | Imago | Octavia E. Butler | Human captive |
| Paul Valéry — Rien du tout, ou la consequence | Rien du tout, ou la consequence | Stanislaw Lem | Poet |
| Pauli — Dreamsnake | Dreamsnake | Vonda N. McIntyre | minor |
| Paz — Imago | Imago | Octavia E. Butler | Human mate to Aaor |
| Peace Makes Plenty — Excession | Excession | Iain M. Banks | Elencher Ship |
| Pedro Leandro Ipuche — Funes the Memorious | Funes the Memorious | Jorge Luis Borges | Writer |
| Peggy Soong(Peggy the Hun) — The Sparrow | The Sparrow | Mary Doria Russell | Co-worker / antagonist to Jimmy |
| Pejar(Dedicat Pejar) — Paladin of Souls | Paladin of Souls | Lois McMaster Bujold | helper |
| Pella — Ammonite | Ammonite | Nicola Griffith | Companion animal |
| Peng-ti — The Years of Rice and Salt | The Years of Rice and Salt | Kim Stanley Robinson | helper |
| Pengefinchess(Penge) — Perdido Street Station | Perdido Street Station | China Miéville | Mercenary adventurer |
| Penny — Timescape | Timescape | Gregory Benford | supporting character |
| Pepper(Jane (birth name), Jane (implied)) — A Closed and Common Orbit | A Closed and Common Orbit | Becky Chambers | human companion / former Jane |
| Peregrine Wickwrackrum(Wickwrackrum, Wickwrackscar, Pilgrim +3) — A Fire Upon the Deep | A Fire Upon the Deep | Vernor Vinge | helper/ally |
| Perry(Prime Minister) — Seven Surrenders | Seven Surrenders | Ada Palmer | European Prime Minister |
| Persian Bookseller — The Approach to Al-Mu'tasim | The Approach to Al-Mu'tasim | Jorge Luis Borges | Merchant |
| Pete — Among Others | Among Others | Jo Walton | minor book club member |
| Pete Griffen — The Ministry for the Future | The Ministry for the Future | Kim Stanley Robinson | Glaciologist |
| Peter — Blue Mars | Blue Mars | Kim Stanley Robinson | Underground contact/engineer |
| Peter — Dawn | Dawn | Octavia E. Butler | Troublemaker and rebel among survivors |
| Peter(Hegemon, Locke) — Ender's Game | Ender's Game | Orson Scott Card | political superior |
| Peter(Pete) — Forever Peace | Forever Peace | Joe Haldeman | opponent/threat |
| Peter — Green Mars | Green Mars | Kim Stanley Robinson | Native Martian / elevator worker |
| Peter(Pete) — Imago | Imago | Octavia E. Butler | Human survivor |
| Peter — Red Mars | Red Mars | Kim Stanley Robinson | Underground operative, Sax's partner on Deimos mission |
| Peter Bogert(Dr. Bogert, Bogert) — I, Robot | I, Robot | Isaac Asimov | Senior mathematician, U.S. Robots |
| Peter Lamont(Pete, Lament) — The Gods Themselves | The Gods Themselves | Isaac Asimov | protagonist |
| Peter Wiggin(Johnny P., Mother, the Hegemon +3) — Ender's Game | Ender's Game | Orson Scott Card | Peter's father / intelligence collaborator |
| Peterson(Ian Peterson) — Timescape | Timescape | Gregory Benford | Actantial sender/opponent; government Council official |
| Petra(Petra Arkanian, Mrs. Delphiki) — Ender's Game | Ender's Game | Orson Scott Card | Bean's companion and strategic partner |
| Petri — The Uplift War | The Uplift War | David Brin | Chim messenger from the mainland |
| Petros(Dr. Ivanov) — Cyteen | Cyteen | C. J. Cherryh | institutional psychologist |
| Pham Nuwen(Emissary Device, Sir Pham) — A Fire Upon the Deep | A Fire Upon the Deep | Vernor Vinge | ambiguous helper/trickster |
| Phil Resch — Do Androids Dream of Electric Sheep? | Do Androids Dream of Electric Sheep? | Philip K. Dick | helper |
| Phil Soames — Hell Is the Absence of God | Hell Is the Absence of God | Ted Chiang | Support group member |
| Philip Guedalla — The Approach to Al-Mu'tasim | The Approach to Al-Mu'tasim | Jorge Luis Borges | Critic |
| Philip Lascaille(Lascaille) — Revelation Space | Revelation Space | Alastair Reynolds | SISS scientist |
| Philip Peterson — Stand on Zanzibar | Stand on Zanzibar | John Brunner | Vignette Character / Mucker Archetype |
| Phoenix — The Will to Battle | The Will to Battle | Ada Palmer | Servicer |
| Phoese Cloathel-Beldrunsa Khoriem lei Poere da'Merire(professor) — Excession | Excession | Iain M. Banks | Human representative |
| Phssthpok — Ringworld | Ringworld | Larry Niven | other |
| Phyllida — The Separation | The Separation | Christopher Priest | supporting |
| Phyllis — Green Mars | Green Mars | Kim Stanley Robinson | Transitional Authority figure / antagonist |
| Phyllis Boyle(Phyllis) — Blue Mars | Blue Mars | Kim Stanley Robinson | Antagonist-adjacent / political informant |
| Phyllis Boyle(Phyllis) — Red Mars | Red Mars | Kim Stanley Robinson | Houston-crowd aligned colonist, top geologist |
| Piali — The Years of Rice and Salt | The Years of Rice and Salt | Kim Stanley Robinson | Physicist, collaborator |
| Pierre Menard — Pierre Menard, Author of the Quixote | Pierre Menard, Author of the Quixote | Jorge Luis Borges | subject/object |
| Pierre Menard — Rien du tout, ou la consequence | Rien du tout, ou la consequence | Stanislaw Lem | Fictional author |
| Pierre Menard — The Circular Ruins | The Circular Ruins | Jorge Luis Borges | Author |
| Pierre Menard — The Form of the Sword | The Form of the Sword | Jorge Luis Borges | Author |
| Pieter Rousseau(Sergeant Pieter Rousseau, Pieter) — Rendezvous with Rama | Rendezvous with Rama | Arthur C. Clarke | Hub observer / reconnaissance specialist |
| Pikes — The Martian Chronicles | The Martian Chronicles | Ray Bradbury | helper |
| Pilun — The Dispossessed | The Dispossessed | Ursula K. Le Guin | Shevek and Takver's baby |
| Pin Xi(Mr Pin) — Air | Air | Geoff Ryman | secondary |
| Pin-Lee — Network Effect | Network Effect | Martha Wells | helper |
| Pipo(João Figueira Alvarez) — Speaker for the Dead | Speaker for the Dead | Orson Scott Card | First Zenador, mentor |
| Piter de Vries(Piter) — Dune | Dune | Frank Herbert | opponent/helper |
| Pittance Store(Pittance) — Excession | Excession | Iain M. Banks | Ship store |
| Playboy — All Tomorrow's Parties | All Tomorrow's Parties | William Gibson | Street thug |
| Plikt — Speaker for the Dead | Speaker for the Dead | Orson Scott Card | Graduate student |
| Plotinus — The Approach to Al-Mu'tasim | The Approach to Al-Mu'tasim | Jorge Luis Borges | Philosopher |
| Plussix(the Blank One) — The Foundation Trilogy | The Foundation Trilogy | Isaac Asimov | Calvinian robot leader / mentor |
| Pollux(Unit Pollux) — The Snow Queen | The Snow Queen | Joan D. Vinge | Polrob, helper |
| Polly Churchill(Polly Sebastian, Viola, Miss Sebastian +1) — Blackout/All Clear | Blackout/All Clear | Connie Willis | Protagonist / stranded historian |
| Polly Wilson — Doomsday Book | Doomsday Book | Connie Willis | Helper |
| Polo — Exhalation | Exhalation | Ted Chiang | Neuroblast digient |
| Polo — The Lifecycle of Software Objects | The Lifecycle of Software Objects | Ted Chiang | Digient |
| Polokov(Sandor Kadalyi) — Do Androids Dream of Electric Sheep? | Do Androids Dream of Electric Sheep? | Philip K. Dick | actantial:opponent |
| Polyphase(Grand Vizier, sage) — The Cyberiad | The Cyberiad | Stanislaw Lem | Adviser to Ferrix |
| Pope Leo XXI(Leo Pappas XXI, the Holy Father, the Pontiff) — A Canticle for Leibowitz | A Canticle for Leibowitz | Walter M. Miller, Jr. | Sender/Authority |
| Poppy — Stand on Zanzibar | Stand on Zanzibar | John Brunner | Vignette Character |
| Porphyre — Mona Lisa Overdrive | Mona Lisa Overdrive | William Gibson | Hairdresser / Confidant |
| Portia(slime mold) — Echopraxia | Echopraxia | Peter Watts | Extremophile threat |
| Postmaster General(life-size doll, mannequin) — The Second Sally or The Offer of King Krool | The Second Sally or The Offer of King Krool | Stanislaw Lem | Sub-program construct |
| Powell Cagan(Powell, Cagan) — Pushing Ice | Pushing Ice | Alastair Reynolds | DeepShaft Executive |
| Predictor Users / Patients(people, patients) — What's Expected of Us | What's Expected of Us | Ted Chiang | Subject demographic |
| Prefect Ptolemy Armsborder(Armsborder) — Perhaps the Stars | Perhaps the Stars | Ada Palmer | Prefect of the Praetorians |
| Prefect Semaphoros(Prefect, Cinna) — Perhaps the Stars | Perhaps the Stars | Ada Palmer | Imperial officer |
| President — Solaris | Solaris | Stanislaw Lem | Head of the Commission |
| President Brannan(Acting President Brannan) — The Calculating Stars | The Calculating Stars | Mary Robinette Kowal | sender |
| President of the Senate of the Nation of A-Io — The Dispossessed | The Dispossessed | Ursula K. Le Guin | Political figure |
| President Scranton — Timescape | Timescape | Gregory Benford | minor |
| Preston Gordon(Preston) — Fledgling | Fledgling | Octavia E. Butler | Elderfather of the Gordon Ina family |
| Prince de Chartreuse — Gruppenfuhrer Louis XVI | Gruppenfuhrer Louis XVI | Stanislaw Lem | Courtier |
| Prince Pantagoon(prince, son) — The Cyberiad | The Cyberiad | Stanislaw Lem | Royalty |
| Prince Pantagoon(heir to the throne, His Majesty, Your son) — The Fourth Sally or How Trurl Built a Femfatalatron | The Fourth Sally or How Trurl Built a Femfatalatron | Stanislaw Lem | Crown prince |
| Prince Red(Prince, the corpse) — Nova | Nova | Samuel R. Delany | Lorq's childhood rival |
| Princesa de Faucigny Lucinge(La princesa) — Ficciones (Tlön, Uqbar, Orbis Tertius) | Ficciones (Tlön, Uqbar, Orbis Tertius) | Jorge Luis Borges | Recipient of an artifact |
| Princess Arjumand(Juju) — To Say Nothing of the Dog | To Say Nothing of the Dog | Connie Willis | Tossie's cat / incongruity object |
| Princess Crystal(Crystal) — The Cyberiad | The Cyberiad | Stanislaw Lem | Royalty |
| Princess Ineffabelle(Ineffabelle) — The Cyberiad | The Cyberiad | Stanislaw Lem | Fictional princess |
| Princess Kareen(Princess-dowager Kareen) — Barrayar | Barrayar | Lois McMaster Bujold | actantial object |
| Princesse Danaë(Danaë, Princesse) — Too Like the Lightning | Too Like the Lightning | Ada Palmer | Royal and political figure |
| Prior Gault(Gault, Father Gault) — A Canticle for Leibowitz | A Canticle for Leibowitz | Walter M. Miller, Jr. | actantial:helper |
| Pris Stratton(Pris) — Do Androids Dream of Electric Sheep? | Do Androids Dream of Electric Sheep? | Philip K. Dick | opponent |
| Private Croucher(Coward, Traitor, Deserter) — The Will to Battle | The Will to Battle | Ada Palmer | Taunting accomplice |
| Professor Alfred Testa — New Cosmogony | New Cosmogony | Stanislaw Lem | Speaker and Nobel laureate |
| Professor Bedřich Vrchlicka — De Impossibilitate Vitae / De Impossibilitate Prognoscendi | De Impossibilitate Vitae / De Impossibilitate Prognoscendi | Stanislaw Lem | Critic |
| Professor Ben-Nour — New Cosmogony | New Cosmogony | Stanislaw Lem | Academic author |
| Professor Bernard Weydenthal — New Cosmogony | New Cosmogony | Stanislaw Lem | Historian of science |
| Professor Bernardo de la Paz(Prof, Bill, Ambassador de la Paz +2) — The Moon Is a Harsh Mistress | The Moon Is a Harsh Mistress | Robert A. Heinlein | Revolutionary theorist and elder strategist |
| Professor Bowman — New Cosmogony | New Cosmogony | Stanislaw Lem | Leader of a research group |
| Professor Chance — Childhood's End | Childhood's End | Arthur C. Clarke | Academic |
| Professor Crusticus(Crusticus) — The Cyberiad | The Cyberiad | Stanislaw Lem | Expert in secret writing |
| Professor Dobb — Non Serviam | Non Serviam | Stanislaw Lem | Creator / Experimenter / Narrator (Afterword) |
| Professor Ernst Ahrens(Ahrens) — A Perfect Vacuum | A Perfect Vacuum | Stanislaw Lem | Teacher |
| Professor Ernst Ahrens(Ahrens) — New Cosmogony | New Cosmogony | Stanislaw Lem | Teacher |
| Professor Evelyn G. Hutchinson(Prof. E. G. Hutchinson) — Odysseus of Ithaca | Odysseus of Ithaca | Stanislaw Lem | Victim/Catalyst |
| Professor Harlan Stymington — New Cosmogony | New Cosmogony | Stanislaw Lem | Academic author |
| Professor Hegramet — Gateway | Gateway | Frederik Pohl | sender |
| Professor Overforce — To Say Nothing of the Dog | To Say Nothing of the Dog | Connie Willis | Antagonist (intellectual) |
| Professor Peddick(Professor Matthew Peddick) — To Say Nothing of the Dog | To Say Nothing of the Dog | Connie Willis | Comic obstacle/helper |
| Professor Pieixoto(James Darcy Pieixoto) — The Handmaid's Tale | The Handmaid's Tale | Margaret Atwood | Academic narrator/frame voice |
| Professor Sessui — The Fountains of Paradise | The Fountains of Paradise | Arthur C. Clarke | actantial:receiver |
| Professor Sullivan(Sullivan) — Childhood's End | Childhood's End | Arthur C. Clarke | helper |
| Professor Zimbalist(Itzik Zimbalist, the boundary maven) — The Yiddish Policemen's Union | The Yiddish Policemen's Union | Michael Chabon | actantial:opponent |
| Prothon(General Prothon) — The Foundation Trilogy | The Foundation Trilogy | Isaac Asimov | Imperial military Protector |
| Pryor — Agency | Agency | William Gibson | Mercenary fixer |
| Psin — The Years of Rice and Salt | The Years of Rice and Salt | Kim Stanley Robinson | supporting |
| Pugg(Ph.D. pirate, thief with a degree) — The Cyberiad | The Cyberiad | Stanislaw Lem | Pirate |
| Pugg(The PHT Pirate, pirate with a Ph.D.) — The Sixth Sally or How Trurl and Klapaucius Created a Demon | The Sixth Sally or How Trurl and Klapaucius Created a Demon | Stanislaw Lem | Robber-giant |
| Pumpington — The Second Sally or The Offer of King Krool | The Second Sally or The Offer of King Krool | Stanislaw Lem | Former Constructor |
| Purple — The Diamond Age | The Diamond Age | Neal Stephenson | Companion/helper (within Primer) |
| Pye — Count Zero | Count Zero | William Gibson | Street medic |
| Quadrumanous protohuman primatrice(quadrumanal female, quadrumaness) — De Impossibilitate Vitae / De Impossibilitate Prognoscendi | De Impossibilitate Vitae / De Impossibilitate Prognoscendi | Stanislaw Lem | Protohuman ancestor |
| Quara — Speaker for the Dead | Speaker for the Dead | Orson Scott Card | Novinha's youngest daughter |
| Queen of the Yahoos(queen) — Tlön, Uqbar, Orbis Tertius | Tlön, Uqbar, Orbis Tertius | Jorge Luis Borges | Consort |
| Queen Oriana(the queen, Oriana) — Queen of the States | Queen of the States | Lisa Goldstein | Sender / faerie queen |
| Quentin(Quentin AQ-8) — Cyteen | Cyteen | C. J. Cherryh | Alpha-class azi security |
| Queter — Ancillary Sword | Ancillary Sword | Ann Leckie | Samirend field worker / witness |
| Queue — Hyperion | Hyperion | Dan Simmons | Suspect/fugitive |
| Quim(Estevão) — Speaker for the Dead | Speaker for the Dead | Orson Scott Card | Novinha's devout Catholic son |
| Quindor Shandess(First Speaker, the twenty-fifth First Speaker) — Foundation's Edge | Foundation's Edge | Isaac Asimov | First Speaker of the Second Foundation |
| Quintesetz(S.Q.) — Foundation's Edge | Foundation's Edge | Isaac Asimov | Sayshellian academic / reluctant informant |
| Quiroga — Tlön, Uqbar, Orbis Tertius | Tlön, Uqbar, Orbis Tertius | Jorge Luis Borges | Slain Warlord |
| Quoile Napier — The Windup Girl | The Windup Girl | Paolo Bacigalupi | Farang trader |
| Qurdusa — Tower of Babylon | Tower of Babylon | Ted Chiang | Bricklayer |
| R. Daneel Olivaw(Demerzel, Daneel, Eternal) — The Foundation Trilogy | The Foundation Trilogy | Isaac Asimov | Ancient humaniform robot and secret architect |
| Rabelais — A Perfect Vacuum (self-review) | A Perfect Vacuum (self-review) | Stanislaw Lem | Referenced author |
| Rachael Rosen(Rachael) — Do Androids Dream of Electric Sheep? | Do Androids Dream of Electric Sheep? | Philip K. Dick | actantial:opponent/helper |
| Rafael — Imago | Imago | Octavia E. Butler | Human resister |
| Rafi(Rafi Mahmud) — The Coral Bones | The Coral Bones | Jynne Martin | Committee ichthyologist |
| Rainey — Agency | Agency | William Gibson | Wilf Netherton's wife |
| Rainey — The Peripheral | The Peripheral | William Gibson | Netherton's former associate |
| Raja Todor Mal — The Years of Rice and Salt | The Years of Rice and Salt | Kim Stanley Robinson | Opponent |
| Rajit — The Years of Rice and Salt | The Years of Rice and Salt | Kim Stanley Robinson | Supporting |
| Rakshi Sengupta(Rakshi, Rak, Sengupta +1) — Echopraxia | Echopraxia | Peter Watts | Pilot and hacker |
| Raleigh(Raleigh-san) — The Windup Girl | The Windup Girl | Paolo Bacigalupi | Bar owner, Emiko's legal owner |
| Raleigh Curtis(Raleigh) — Fledgling | Fledgling | Octavia E. Butler | Human associate/shooter |
| Ralph — Forever Peace | Forever Peace | Joe Haldeman | Platoon mechanic / horizontal liaison |
| Ralph Summers — A Perfect Vacuum | A Perfect Vacuum | Stanislaw Lem | Fictional Critic |
| Ralph Summers — U-Write-It | U-Write-It | Stanislaw Lem | Literary critic |
| Raltariki — Lord of Light | Lord of Light | Roger Zelazny | Rakasha gambler / provisional antagonist |
| Ram Ibusa — Stand on Zanzibar | Stand on Zanzibar | John Brunner | Beninian finance minister |
| Ramirez — Count Zero | Count Zero | William Gibson | Console jockey |
| Ramon — Imago | Imago | Octavia E. Butler | Human resister |
| Ramsey — Timescape | Timescape | Gregory Benford | Competitor physicist |
| Randy Shoats(Randall James Branch Cabell Shoats) — All Tomorrow's Parties | All Tomorrow's Parties | William Gibson | Session guitarist |
| Rangolith(Farscout Rangolith) — A Fire Upon the Deep | A Fire Upon the Deep | Vernor Vinge | minor/military |
| Raniya — The Merchant and the Alchemist's Gate | The Merchant and the Alchemist's Gate | Ted Chiang | Hassan's wife |
| Ras(stablemaster) — Dreamsnake | Dreamsnake | Vonda N. McIntyre | opponent |
| Ras(Casualty Two) — Network Effect | Network Effect | Martha Wells | Barish-Estranza corporate survivor |
| Rashaverak(Rashy) — Childhood's End | Childhood's End | Arthur C. Clarke | Overlord observer |
| Rashid Niazi — Red Mars | Red Mars | Kim Stanley Robinson | secondary |
| Rashiel — Hell Is the Absence of God | Hell Is the Absence of God | Ted Chiang | Angel |
| Rask — The Fifth Season | The Fifth Season | N.K. Jemisin | Tirimo comm member |
| Raspberry — Stories of Your Life and Others | Stories of Your Life and Others | Ted Chiang | Heptapod alien |
| Raspberry — Story of Your Life | Story of Your Life | Ted Chiang | Alien |
| Rat Korga(Prince Charming, Korga, the survivor +7) — Stars in My Pocket Like Grains of Sand | Stars in My Pocket Like Grains of Sand | Samuel R. Delany | Survivor / Romantic Partner |
| Ratana — The Windup Girl | The Windup Girl | Paolo Bacigalupi | Ministry laboratory scientist |
| Raton — All Tomorrow's Parties | All Tomorrow's Parties | William Gibson | Street thug |
| Ratri(Goddess Ratri, Lady of Night, Night Immortal +2) — Lord of Light | Lord of Light | Roger Zelazny | Helper / Sender |
| Ratthi(Dr. Ratthi) — Network Effect | Network Effect | Martha Wells | Crew member |
| Raven — Snow Crash | Snow Crash | Neal Stephenson | actantial:opponent |
| Ravna(Ravna Bergsndot, My Lady Ravna) — A Fire Upon the Deep | A Fire Upon the Deep | Vernor Vinge | protagonist / actantial subject |
| Ray(Elbe) — Forever Peace | Forever Peace | Joe Haldeman | Researcher, member of the Twenty |
| Rear Admiral Lee(Commander William Ajunta Lee, Lee) — The Fall of Hyperion | The Fall of Hyperion | Dan Simmons | Military strategist / hero of Maui-Covenant |
| Reardon — Blackout/All Clear | Blackout/All Clear | Connie Willis | Contemp companion |
| Rebecca Boyer — Liking What You See: A Documentary | Liking What You See: A Documentary | Ted Chiang | Spokesperson for People for Ethical Nanomedicine |
| Rebecca Byers(Becca) — Ancillary Sword | Ancillary Sword | Ann Leckie | communications officer |
| Recabarren — The End | The End | Jorge Luis Borges | Frame witness / bar owner |
| Red Cross tribunal observer — The Separation | The Separation | Christopher Priest | Narrator (documentary frame) |
| Red Scharlach(Scharlach the Dandy) — Death and the Compass | Death and the Compass | Jorge Luis Borges | Criminal mastermind |
| Red Scharlach(Gryphius, Ginzberg, Ginsburg) — Tlön, Uqbar, Orbis Tertius | Tlön, Uqbar, Orbis Tertius | Jorge Luis Borges | Gangster / Murderer |
| Red-haired man — Imago | Imago | Octavia E. Butler | Human raider |
| Reece — The Peripheral | The Peripheral | William Gibson | Army veteran / Security |
| Reed — Blackout/All Clear | Blackout/All Clear | Connie Willis | FANY unit member |
| Reed Weber — Rainbows End | Rainbows End | Vernor Vinge | helper |
| Rei Toei(The idoru, kind one, bright one +1) — All Tomorrow's Parties | All Tomorrow's Parties | William Gibson | Holographic AI entity |
| Rei Toei(The idoru) — Idoru | Idoru | William Gibson | Virtual pop star |
| Reinhold — Childhood's End | Childhood's End | Arthur C. Clarke | German rocket engineer |
| Reiss — Exhalation | Exhalation | Ted Chiang | Researcher |
| Reiss — The Truth of Fact, the Truth of Feeling | The Truth of Fact, the Truth of Feeling | Ted Chiang | European Anthropologist |
| Relman — Ammonite | Ammonite | Nicola Griffith | Mirror officer |
| Relstoch Sussepin(Mr. Sussepin) — Use of Weapons | Use of Weapons | Iain M. Banks | Composer |
| Rem (Duval's Remote operator) — The Fountains of Paradise | The Fountains of Paradise | Arthur C. Clarke | Technical helper |
| Renee(Mrs. Norwood) — Division by Zero | Division by Zero | Ted Chiang | Professor of mathematics |
| Renee(Mrs. Norwood) — Stories of Your Life and Others | Stories of Your Life and Others | Ted Chiang | Mathematician |
| Renfrew(Marjorie, Marjorie Renfrew, John +1) — Timescape | Timescape | Gregory Benford | Protagonist (1998 thread); experimental physicist |
| Revd Michael Hutchinson — The Separation | The Separation | Christopher Priest | Tribunal member |
| Reverend Mother Gaius Helen Mohiam(Decidora de Verdad) — Dune | Dune | Frank Herbert | Bene Gesserit Censor |
| Reverend Mother Ramallo — Dune | Dune | Frank Herbert | actantial:donor |
| Reverend Norris — Blackout/All Clear | Blackout/All Clear | Connie Willis | minor |
| Rex Foster-Stern — Stand on Zanzibar | Stand on Zanzibar | John Brunner | GT senior VP, projects and planning |
| Reynolds — Stories of Your Life and Others | Stories of Your Life and Others | Ted Chiang | Antagonist |
| Reynolds — Understand | Understand | Ted Chiang | Enhanced patient / Antagonist |
| Rez(our friend, Rozzer) — Idoru | Idoru | William Gibson | Global rock star |
| Reza — Forever Peace | Forever Peace | Joe Haldeman | Friend, social circle member |
| Rheya — Solaris | Solaris | Stanislaw Lem | Alien-generated construct of Kelvin's deceased wife |
| Rhonda — The Forever War | The Forever War | Joe Haldeman | Mandella's mother's companion |
| Richard Burton — The Approach to Al-Mu'tasim | The Approach to Al-Mu'tasim | Jorge Luis Borges | Author / Translator |
| Richard William Church — The Approach to Al-Mu'tasim | The Approach to Al-Mu'tasim | Jorge Luis Borges | Critic |
| Rick(Ricky) — Klara and the Sun | Klara and the Sun | Kazuo Ishiguro | Josie's neighbor and friend |
| Rick Deckard(Iran, bounty hunter, Mr. Deckard +1) — Do Androids Dream of Electric Sheep? | Do Androids Dream of Electric Sheep? | Philip K. Dick | protagonist |
| Rico(Johnnie) — Starship Troopers | Starship Troopers | Robert A. Heinlein | protagonist |
| Rico's father(Father, Juan's father) — Starship Troopers | Starship Troopers | Robert A. Heinlein | Parent / late enlistee |
| Rild(Sugata, the small man, the second Buddha) — Lord of Light | Lord of Light | Roger Zelazny | antagonist-turned-disciple |
| Ringer — Virtual Light | Virtual Light | William Gibson | Vandal |
| Rita — The Handmaid's Tale | The Handmaid's Tale | Margaret Atwood | Martha in the Commander's household |
| Roa — Network Effect | Network Effect | Martha Wells | Baseship pilot |
| Roadkill — Snow Crash | Snow Crash | Neal Stephenson | minor |
| Roald — Blue Mars | Blue Mars | Kim Stanley Robinson | actantial:helper |
| Rob — The Coral Bones | The Coral Bones | Jynne Martin | helper |
| Rob Broadhead(Robbie, Rob, Robinette +1) — Gateway | Gateway | Frederik Pohl | Protagonist/Narrator |
| Robbie — I, Robot | I, Robot | Isaac Asimov | actantial:object |
| Robert — The Martian Chronicles | The Martian Chronicles | Ray Bradbury | Middle son |
| Robert Cecil — Queen of the States | Queen of the States | Lisa Goldstein | Star Chamber judge |
| Robert Cunningham(Robert, Cunningham) — Blindsight | Blindsight | Peter Watts | Biologist / Medical Officer |
| Robert Gu(You-Know-Who, Professor Gu, Dad +2) — Rainbows End | Rainbows End | Vernor Vinge | protagonist |
| Robert Oneagle(Robert, Captain Oneagle, Refuge Administrator +1) — The Uplift War | The Uplift War | David Brin | Human guerrilla fighter, Athaclena's consort |
| Robert Paglino(Pag) — Blindsight | Blindsight | Peter Watts | Siri's childhood friend |
| Robert Poley(Robert, Master Poley) — Queen of the States | Queen of the States | Lisa Goldstein | actantial sender/opponent |
| Robert Stratton(Stratton, Mr. Stratton) — Seventy-Two Letters | Seventy-Two Letters | Ted Chiang | Protagonist, nomenclator |
| Roberto — New York 2140 | New York 2140 | Kim Stanley Robinson | Skimboarder |
| Robertson — I, Robot | I, Robot | Isaac Asimov | Chief executive, U.S. Robots |
| Robertson — Three Versions of Judas | Three Versions of Judas | Jorge Luis Borges | Scholar |
| Robin Pearson — Hell Is the Absence of God | Hell Is the Absence of God | Ted Chiang | Bereaved widow |
| Robinson — A Perfect Vacuum | A Perfect Vacuum | Stanislaw Lem | Protagonist |
| Robinson(Sergius N., Master, Cock Robinson +1) — Les Robinsonades | Les Robinsonades | Stanislaw Lem | Protagonist / Creator |
| Roboy(Dr. Roboy) — The Yiddish Policemen's Union | The Yiddish Policemen's Union | Michael Chabon | Antagonist-helper / true believer |
| Robyn — Exhalation | Exhalation | Ted Chiang | Blue Gamma Employee |
| Robyn — The Lifecycle of Software Objects | The Lifecycle of Software Objects | Ted Chiang | Blue Gamma employee |
| Rocher — Cyteen | Cyteen | C. J. Cherryh | Abolitionist leader |
| Roderick Ferris(Roderick) — Anxiety Is the Dizziness of Freedom | Anxiety Is the Dizziness of Freedom | Ted Chiang | Scott's Husband, Movie Star |
| Rodney(Rod) — Never Let Me Go | Never Let Me Go | Kazuo Ishiguro | Veteran student at the Cottages |
| Roger Swain(Swain) — Mona Lisa Overdrive | Mona Lisa Overdrive | William Gibson | London rackets boss |
| Rogtam-Bar(Bar) — Use of Weapons | Use of Weapons | Iain M. Banks | Junior commander |
| Roland — Timescape | Timescape | Gregory Benford | Farmhouse factotum |
| Roland Barthes — Rien du tout, ou la consequence | Rien du tout, ou la consequence | Stanislaw Lem | Essayist |
| Ronald Schuer — A Perfect Vacuum | A Perfect Vacuum | Stanislaw Lem | Fictional author/theorist |
| Ronald Schuer — New Cosmogony | New Cosmogony | Stanislaw Lem | Theoretician |
| Rooter — Speaker for the Dead | Speaker for the Dead | Orson Scott Card | Piggy leader (early) |
| Rorschach — Blindsight | Blindsight | Peter Watts | Alien Artefact |
| Rosa — Klara and the Sun | Klara and the Sun | Kazuo Ishiguro | Artificial Friend |
| Rosas — Tlön, Uqbar, Orbis Tertius | Tlön, Uqbar, Orbis Tertius | Jorge Luis Borges | Deceased Dictator |
| Rosemary — Omphalos | Omphalos | Ted Chiang | Dorothea's cousin |
| Rosemund — Doomsday Book | Doomsday Book | Connie Willis | supporting |
| Rosendo Juárez(the Sticker) — The Form of the Sword | The Form of the Sword | Jorge Luis Borges | Knife fighter |
| Rosendo Juárez(the Sticker) — Tlön, Uqbar, Orbis Tertius | Tlön, Uqbar, Orbis Tertius | Jorge Luis Borges | Narrator/Former Enforcer |
| Rowan Durona(Chrys, Dr. R. Durona, Dr. R.) — Mirror Dance | Mirror Dance | Lois McMaster Bujold | exposition figure/sender |
| Roy Baty(Irm, Mrs. Baty, Mr. Baty) — Do Androids Dream of Electric Sheep? | Do Androids Dream of Electric Sheep? | Philip K. Dick | opponent |
| Ruby Barnes(Sergeant Barnes, Sergeant Ruby Barnes, Sergeant) — Rendezvous with Rama | Rendezvous with Rama | Arthur C. Clarke | crew member / helmsman |
| Ruby Red(Ruby, Queen of Swords) — Nova | Nova | Samuel R. Delany | Prince's loyal sister |
| Rudolf Hess(Herr Deputy Führer, Herr Deputy Leader, Fraulein Hess) — The Separation | The Separation | Christopher Priest | Actantial helper / historical figure |
| Rudra — Lord of Light | Lord of Light | Roger Zelazny | opponent |
| Rudyard Kipling — The Approach to Al-Mu'tasim | The Approach to Al-Mu'tasim | Jorge Luis Borges | Author |
| Rulag — The Dispossessed | The Dispossessed | Ursula K. Le Guin | Shevek's estranged mother and PDC member |
| Rupert — Childhood's End | Childhood's End | Arthur C. Clarke | Wealthy socialite |
| Russell Silk(Russell) — Fledgling | Fledgling | Octavia E. Butler | Accused Ina |
| Russian chess player — The Yiddish Policemen's Union | The Yiddish Policemen's Union | Michael Chabon | minor witness |
| Ruth — Never Let Me Go | Never Let Me Go | Kazuo Ishiguro | Kathy's friend and Hailsham student |
| Ruth(Ruthie) — Stranger in a Strange Land | Stranger in a Strange Land | Robert A. Heinlein | actantial:helper |
| Ruth Campbell(Ruth) — Among Others | Among Others | Jo Walton | minor antagonist / authority |
| Ruth Shoenberger(Benny, Ruth) — Childhood's End | Childhood's End | Arthur C. Clarke | supporting |
| Rya Jimenez — Blue Mars | Blue Mars | Kim Stanley Robinson | Crew member / pilot |
| Ryan — The Circular Ruins | The Circular Ruins | Jorge Luis Borges | Investigator |
| Ryan — Theme of the Traitor and the Hero | Theme of the Traitor and the Hero | Jorge Luis Borges | Biographer / Investigator |
| Ryan Axford(Ryan, Axford) — Pushing Ice | Pushing Ice | Alastair Reynolds | Ship's Surgeon |
| Rydell(Mr. Rydell, Berry Rydell) — All Tomorrow's Parties | All Tomorrow's Parties | William Gibson | Former security guard / courier |
| Ryoval's technician — Mirror Dance | Mirror Dance | Lois McMaster Bujold | opponent |
| S. Lem — A Perfect Vacuum | A Perfect Vacuum | Stanislaw Lem | Reviewer/Author |
| S. Lem(Lem, Author) — A Perfect Vacuum (self-review) | A Perfect Vacuum (self-review) | Stanislaw Lem | Author |
| S. Ya. Lavorovna — Gateway | Gateway | Frederik Pohl | Current girlfriend |
| Saaz Insile — Use of Weapons | Use of Weapons | Iain M. Banks | Fellow pilot |
| Sabe — Exhalation | Exhalation | Ted Chiang | Tiv Elder / Chief |
| Sabe — The Truth of Fact, the Truth of Feeling | The Truth of Fact, the Truth of Feeling | Ted Chiang | Tiv Elder and Chief |
| Sabiha Gökçen — The Calculating Stars | The Calculating Stars | Mary Robinette Kowal | helper |
| Sabina — Imago | Imago | Octavia E. Butler | Resister |
| Sabina Dobrowski(Sabina) — Adulthood Rites | Adulthood Rites | Octavia E. Butler | Salvager |
| Sabul — The Dispossessed | The Dispossessed | Ursula K. Le Guin | Anarresti physicist |
| Sachita Bhar(Sachie) — Echopraxia | Echopraxia | Peter Watts | Research associate |
| Sad King Billy(King William) — Hyperion | Hyperion | Dan Simmons | Eccentric royal patron |
| Sad King Billy(Billy, my lord) — The Fall of Hyperion | The Fall of Hyperion | Dan Simmons | Patron / historical figure |
| Sadik — The Dispossessed | The Dispossessed | Ursula K. Le Guin | Shevek and Takver's daughter |
| Sah'ot — Startide Rising | Startide Rising | David Brin | Neo-dolphin linguist on the skiff |
| Saint Rihndell — A Fire Upon the Deep | A Fire Upon the Deep | Vernor Vinge | transactional ally |
| Saio Pae(Pae) — The Dispossessed | The Dispossessed | Ursula K. Le Guin | Shevek's Escort/Companion |
| Sal(Miss Sal) — Klara and the Sun | Klara and the Sun | Kazuo Ishiguro | Josie's deceased sister |
| Saladin — Perhaps the Stars | Perhaps the Stars | Ada Palmer | Deceased Companion |
| Salas — The Dispossessed | The Dispossessed | Ursula K. Le Guin | Anarresti composer |
| Salewha — The Stone Sky | The Stone Sky | N. K. Jemisin | helper (deep past) |
| Sally Shears(Sally) — Mona Lisa Overdrive | Mona Lisa Overdrive | William Gibson | Mercenary / Kumiko's protector |
| Saltiel Lapidus — The Yiddish Policemen's Union | The Yiddish Policemen's Union | Michael Chabon | witness |
| Sam — Among Others | Among Others | Jo Walton | paternal grandfather / helper |
| Sam — Dawn | Dawn | Octavia E. Butler | Lilith's deceased husband |
| Sam — Green Mars | Green Mars | Kim Stanley Robinson | Fellow seminar recruit |
| Sam(Mahasamatman, Siddhartha, Tathagatha +10) — Lord of Light | Lord of Light | Roger Zelazny | protagonist / teacher |
| Sam — Stranger in a Strange Land | Stranger in a Strange Land | Robert A. Heinlein | Nest member/strategist |
| Sam — The Separation | The Separation | Christopher Priest | Navigator, crew member narrator |
| Sam Black Crow(Sam, Sammy, Auntie Sammy) — American Gods | American Gods | Neil Gaiman | significant minor human |
| Sam Houston — Blue Mars | Blue Mars | Kim Stanley Robinson | UNOMA/FBI investigator |
| Sam Houston(Houston) — Red Mars | Red Mars | Kim Stanley Robinson | opponent |
| Sam Kahane — Gateway | Gateway | Frederik Pohl | supporting |
| Sam Parkhill(Sam) — The Martian Chronicles | The Martian Chronicles | Ray Bradbury | Crewman, Fourth Expedition |
| Samantha — Blue Mars | Blue Mars | Kim Stanley Robinson | minor |
| Samantha — Forever Peace | Forever Peace | Joe Haldeman | Platoon mechanic |
| Samantha Martinez — Redshirts | Redshirts | John Scalzi | Actress / real-world counterpart of Margaret Jenkins |
| Sammy Sal — Virtual Light | Virtual Light | William Gibson | Bike Messenger |
| Samuel Teece(Mrs. Teece, Teece, Samuel W. Teece) — The Martian Chronicles | The Martian Chronicles | Ray Bradbury | opponent |
| Sand — Dreamsnake | Dreamsnake | Vonda N. McIntyre | helper / instrument |
| Sandra — Redshirts | Redshirts | John Scalzi | Law intern / Helper |
| Sandy Hereld(Lieutenant Hereld) — Mirror Dance | Mirror Dance | Lois McMaster Bujold | Dendarii communications officer |
| Sandy-haired woman(the little sandy-haired woman) — 1984 | 1984 | George Orwell | minor character |
| Santesteban — The Forever War | The Forever War | Joe Haldeman | platoon sergeant |
| Santine(Skya Santine) — Stars in My Pocket Like Grains of Sand | Stars in My Pocket Like Grains of Sand | Samuel R. Delany | Transport Driver |
| Santos Ibarra Ruiz(Santos) — Imago | Imago | Octavia E. Butler | Human resister |
| Sara Hiam(Hiam, the doctor) — Ammonite | Ammonite | Nicola Griffith | Helper/Institutional gatekeeper |
| Sarah Ferguson(Sarah) — Spook Country | Spook Country | William Gibson | Gallery worker / Bobby's sister |
| Sarah's parents — Hell Is the Absence of God | Hell Is the Absence of God | Ted Chiang | In-laws |
| Sarai — Hyperion | Hyperion | Dan Simmons | Sol's wife/Rachel's mother |
| Sartorius(Dr. Sartorius) — Solaris | Solaris | Stanislaw Lem | Colleague on the Station |
| Sasha — Blue Mars | Blue Mars | Kim Stanley Robinson | First hundred member |
| Sasha — Red Mars | Red Mars | Kim Stanley Robinson | Member of the first hundred, casualty |
| Saskia(First Officer Zodiac, Saskia Zodiac) — Take Back Plenty | Take Back Plenty | Colin Greenland | Zodiac Twin (female), acrobatic performer |
| Satsuma man — The Form of the Sword | The Form of the Sword | Jorge Luis Borges | Pilgrim |
| Saul — Stranger in a Strange Land | Stranger in a Strange Land | Robert A. Heinlein | Nest member |
| Saul Evans(The Lighthouse Keeper, Saul, Mr. Evans) — Acceptance | Acceptance | Jeff VanderMeer | Lighthouse keeper |
| Saul Evans — Authority | Authority | Jeff VanderMeer | Lighthouse keeper |
| Saul Shriffer(Saul, Schriffer) — Timescape | Timescape | Gregory Benford | Helper turned complication |
| Sax(Sax Russell, Saxifrage Russell, Stephen Lindholm +1) — Blue Mars | Blue Mars | Kim Stanley Robinson | Terraforming scientist, resistance weapons designer |
| Sax(Stephen) — Green Mars | Green Mars | Kim Stanley Robinson | Terraforming scientist, underground operative |
| Sax(Russell, Saxifrage Russell, Stephen Lindholm +3) — Red Mars | Red Mars | Kim Stanley Robinson | Atmospheric scientist, terraforming architect |
| Sax Russell(Stephen Lindholm, Lindholm, Stephen +1) — Green Mars | Green Mars | Kim Stanley Robinson | Terraforming scientist; covert revolutionary strategist |
| Scatha — Ammonite | Ammonite | Nicola Griffith | Aelle's daughter |
| Schaffa(Schaffa Guardian Warrant) — The Stone Sky | The Stone Sky | N. K. Jemisin | Guardian / surrogate father to Nassun |
| Schaffa Guardian Warrant(Schaffa, Guardian) — The Fifth Season | The Fifth Season | N.K. Jemisin | Damaya's Guardian |
| Scharlach's brother — Death and the Compass | Death and the Compass | Jorge Luis Borges | Catalyst character |
| Scherzinger(M. Scherzinger) — The Calculating Stars | The Calculating Stars | Mary Robinette Kowal | sender |
| Schopenhauer — Die Kultur als Fehler | Die Kultur als Fehler | Stanislaw Lem | Historical Philosopher |
| Scott Otsuka(Scott) — Anxiety Is the Dizziness of Freedom | Anxiety Is the Dizziness of Freedom | Ted Chiang | Wealthy Widower, Pop Singer |
| Scoville — Forever Peace | Forever Peace | Joe Haldeman | Hunter-killer platoon leader |
| Scriber(Jaque-what's-his-name, Jaqueramaphan, Scriber Jaqueramaphan) — A Fire Upon the Deep | A Fire Upon the Deep | Vernor Vinge | helper |
| Scrupilo(White Head, Scrup, Commander of Cannoneers) — A Fire Upon the Deep | A Fire Upon the Deep | Vernor Vinge | actantial helper / council member |
| Sebastian(the stud) — Nova | Nova | Samuel R. Delany | Crewmate / Animal tamer |
| Second — A Desolation Called Peace | A Desolation Called Peace | Arkady Martine | Alien contact individual |
| Secretary General Douglas(Mr. Secretary General, Joseph E. Douglas, Mr. Secretary +4) — Stranger in a Strange Land | Stranger in a Strange Land | Robert A. Heinlein | Political antagonist and negotiating partner |
| Secretary Lu — Cyteen | Cyteen | C. J. Cherryh | Secretary of Defense; Centrist operative |
| SecUnit(SecUnit 003, 3, 2.0's SecUnit 3 +6) — Network Effect | Network Effect | Martha Wells | Narrator / protagonist / rogue construct bodyguard |
| Sedeptra Akasi — The Fall of Hyperion | The Fall of Hyperion | Dan Simmons | Gladstone's aide |
| Sedjar Boon(Boon) — The Foundation Trilogy | The Foundation Trilogy | Isaac Asimov | Defense advocate |
| Seeker — Ringworld | Ringworld | Larry Niven | other |
| Seely — Cyteen | Cyteen | C. J. Cherryh | Denys's azi / security operative |
| Sehanol — Ammonite | Ammonite | Nicola Griffith | actantial:helper |
| Seivarden(Captain Seivarden, Seivarden Vendaai, citizen) — Ancillary Justice | Ancillary Justice | Ann Leckie | Companion (reluctant) |
| Seivarden(Lieutenant Seivarden) — Ancillary Sword | Ancillary Sword | Ann Leckie | Senior lieutenant aboard Mercy of Kalr |
| Sek Hardeen(True Voice of the Worldtree) — The Fall of Hyperion | The Fall of Hyperion | Dan Simmons | Templar leader |
| Sel'v — Stars in My Pocket Like Grains of Sand | Stars in My Pocket Like Grains of Sand | Samuel R. Delany | Family Member |
| Selene(Selene Lindstrom, Miss Lindstrom) — The Gods Themselves | The Gods Themselves | Isaac Asimov | Lunarite tourist guide; Part 3 protagonist |
| Selim(Sultan Selim the Third, the Sultan) — The Years of Rice and Salt | The Years of Rice and Salt | Kim Stanley Robinson | Ottoman Sultan Caliph |
| Selim el-Hayil — Blue Mars | Blue Mars | Kim Stanley Robinson | Deceased Arab conspirator |
| Selim el-Hayil — Red Mars | Red Mars | Kim Stanley Robinson | Deceased Ahad militant |
| Selwyn-Thaxted(Mr Selwyn-Thaxted) — The Separation | The Separation | Christopher Priest | helper |
| Senator Boone(Bishop Senator Boone) — Stranger in a Strange Land | Stranger in a Strange Land | Robert A. Heinlein | Fosterite political operative |
| Senator Burt(Senator Hurt) — The Gods Themselves | The Gods Themselves | Isaac Asimov | opponent |
| Senator Collins — The Fountains of Paradise | The Fountains of Paradise | Arthur C. Clarke | Political antagonist / TCC Chairman |
| Senator Feldstein(Dorothy) — The Fall of Hyperion | The Fall of Hyperion | Dan Simmons | Senator from Barnard's World |
| Senator Kolchev — The Fall of Hyperion | The Fall of Hyperion | Dan Simmons | Senator / war council member |
| Senator Mason — The Calculating Stars | The Calculating Stars | Mary Robinette Kowal | minor |
| Senior Detective Dhatt(Dhatt, SD) — The City & The City | The City & The City | China Miéville | Ul Qoman militsya officer |
| Senior Security(Senior Security officer) — Ancillary Justice | Ancillary Justice | Ann Leckie | actantial:receiver |
| Senmut — Tower of Babylon | Tower of Babylon | Ted Chiang | Foreman of the Egyptians |
| Senora Madero(Senora, unnamed mayor of San Ignacio) — Forever Peace | Forever Peace | Joe Haldeman | Rebel leader, prisoner |
| Serena Joy — The Handmaid's Tale | The Handmaid's Tale | Margaret Atwood | Commander's Wife |
| Sergeant Brumby — Starship Troopers | Starship Troopers | Robert A. Heinlein | helper/squad leader |
| Sergeant Cunha — Starship Troopers | Starship Troopers | Robert A. Heinlein | helper/section leader |
| Sergeant Framingham — Mirror Dance | Mirror Dance | Lois McMaster Bujold | minor officer |
| Sergeant Jelal(Jelly) — Starship Troopers | Starship Troopers | Robert A. Heinlein | section leader / de facto platoon sergeant |
| Sergeant Myron — Rendezvous with Rama | Rendezvous with Rama | Arthur C. Clarke | supporting |
| Sergeant Taura — Mirror Dance | Mirror Dance | Lois McMaster Bujold | helper |
| Sergeant Zim — Starship Troopers | Starship Troopers | Robert A. Heinlein | drill instructor / company commander |
| Sergei Magomedov(Sergei) — Pattern Recognition | Pattern Recognition | William Gibson | Web-based security operative |
| Sergius — De Impossibilitate Vitae / De Impossibilitate Prognoscendi | De Impossibilitate Vitae / De Impossibilitate Prognoscendi | Stanislaw Lem | Student/Employer |
| Serious Callers Only — Excession | Excession | Iain M. Banks | Ship Mind |
| Servicer Captain — Too Like the Lightning | Too Like the Lightning | Ada Palmer | Servicer |
| Seth — Network Effect | Network Effect | Martha Wells | helper |
| Sevada — Solaris | Solaris | Stanislaw Lem | Historical Solarist |
| Seven Issa(Justice of Ente Seven Issa) — Ancillary Justice | Ancillary Justice | Ann Leckie | Ancillary soldier |
| Sevrin — Agency | Agency | William Gibson | Driver and financial fixer |
| Sezen(Miss Ozdemir, wild girl) — Air | Air | Geoff Ryman | absent figure |
| Shadout Mapes — Dune | Dune | Frank Herbert | helper |
| Shadow(Shadow Moon, Puppy, A. Haddock +3) — American Gods | American Gods | Neil Gaiman | actantial:subject |
| Shadrach — Perdido Street Station | Perdido Street Station | China Miéville | Mercenary adventurer |
| Shalmaneser(Shal) — Stand on Zanzibar | Stand on Zanzibar | John Brunner | oracular presence |
| Sharad — Dawn | Dawn | Octavia E. Butler | Human child (mentioned) |
| Sharon — Blue Mars | Blue Mars | Kim Stanley Robinson | Minor / absent character |
| Shastri — The Years of Rice and Salt | The Years of Rice and Salt | Kim Stanley Robinson | Opponent |
| Shea — Stories of Your Life and Others | Stories of Your Life and Others | Ted Chiang | Doctor |
| Shed Garvey — Ancillary Sword | Ancillary Sword | Ann Leckie | medical tech |
| Sheenie(Terence Sheehan) — The Moon Is a Harsh Mistress | The Moon Is a Harsh Mistress | Robert A. Heinlein | actantial:helper |
| Sheila Hanson — Rainbows End | Rainbows End | Vernor Vinge | other |
| Shemshena — The Fifth Season | The Fifth Season | N.K. Jemisin | Historical figure |
| Shen — The Years of Rice and Salt | The Years of Rice and Salt | Kim Stanley Robinson | supporting |
| Shen Suloi(Suloi, Mrs Shen) — Air | Air | Geoff Ryman | secondary |
| Sheri(Sheri Loffat) — Gateway | Gateway | Frederik Pohl | Companion/Crewmate candidate |
| Shevek(Dr. Shevek, Shev, Moon Man) — The Dispossessed | The Dispossessed | Ursula K. Le Guin | Anarresti physicist and Syndicate founder |
| Shi Fandi — The Years of Rice and Salt | The Years of Rice and Salt | Kim Stanley Robinson | antagonist/officer |
| Shicky Bakin(Shicky, Shikitei Bakin, Bakin) — Gateway | Gateway | Frederik Pohl | Minor/Memory figure |
| Shih — The Years of Rice and Salt | The Years of Rice and Salt | Kim Stanley Robinson | Youth in Kang's household |
| Shill — Ammonite | Ammonite | Nicola Griffith | Helper |
| Shinya Yamazaki(Yamazaki) — All Tomorrow's Parties | All Tomorrow's Parties | William Gibson | Observer/Sociologist |
| Shinya Yamazaki(Yamazaki) — Idoru | Idoru | William Gibson | Student of existential sociology / Observer |
| ship's avatar — Excession | Excession | Iain M. Banks | Avatar |
| Shirk — The Stone Sky | The Stone Sky | N. K. Jemisin | Found Moon orogene child |
| Shiva(Lord of Destruction, the one with the trident) — Lord of Light | Lord of Light | Roger Zelazny | opponent |
| Shkaht — Adulthood Rites | Adulthood Rites | Octavia E. Butler | Construct child |
| Shkaht — Imago | Imago | Octavia E. Butler | Construct child / Captive |
| Shoji(Mr. Fujisaki) — To Say Nothing of the Dog | To Say Nothing of the Dog | Connie Willis | Early Oxford time-travel researcher |
| Shori(Renee, Shori Matthews, Mateescu) — Fledgling | Fledgling | Octavia E. Butler | Protagonist and narrator |
| Shorty Mkrum(Shorty) — The Moon Is a Harsh Mistress | The Moon Is a Harsh Mistress | Robert A. Heinlein | Revolutionary comrade; Wyoh's closest friend in Luna City |
| Shoshana — Stars in My Pocket Like Grains of Sand | Stars in My Pocket Like Grains of Sand | Samuel R. Delany | Parent |
| Shouter — Speaker for the Dead | Speaker for the Dead | Orson Scott Card | Wife / piggy female authority |
| Shprintzl Rudashevsky(Shprintzeleh) — The Yiddish Policemen's Union | The Yiddish Policemen's Union | Michael Chabon | bodyguard/helper |
| Shreck — A Fire Upon the Deep | A Fire Upon the Deep | Vernor Vinge | opponent/lieutenant |
| Siao — Air | Air | Geoff Ryman | Mae's brother-in-law (Joe's brother) |
| Sidra(Lovelace, Lovey, the kit) — A Closed and Common Orbit | A Closed and Common Orbit | Becky Chambers | AI protagonist |
| Siegfried Taudlitz(Louis XVI, His Lordship, His Highness) — Gruppenfuhrer Louis XVI | Gruppenfuhrer Louis XVI | Stanislaw Lem | Former SS Gruppenführer / Fake King |
| Sigfrid(Sigfrid von Shrink, S. Ya.) — Gateway | Gateway | Frederik Pohl | actantial:sender |
| Sigrid — Ammonite | Ammonite | Nicola Griffith | helper |
| Silas Haslam(Haslam) — Ficciones (Tlön, Uqbar, Orbis Tertius) | Ficciones (Tlön, Uqbar, Orbis Tertius) | Jorge Luis Borges | Author |
| Silencio(The boy) — All Tomorrow's Parties | All Tomorrow's Parties | William Gibson | Traumatized boy |
| Silky — The Snow Queen | The Snow Queen | Joan D. Vinge | Non-human companion (dillyp) |
| Silver — Dreamsnake | Dreamsnake | Vonda N. McIntyre | sender |
| Silver-haired lady — Never Let Me Go | Never Let Me Go | Kazuo Ishiguro | Art gallery attendant |
| Silver-haired woman — Ringworld | Ringworld | Larry Niven | opponent |
| Simon — Blue Mars | Blue Mars | Kim Stanley Robinson | Ann's companion |
| Simon — Green Mars | Green Mars | Kim Stanley Robinson | Ann's deceased partner |
| Simon(Simon Frazier) — Red Mars | Red Mars | Kim Stanley Robinson | Survey team member, Ann's partner |
| Simon Illyan — Mirror Dance | Mirror Dance | Lois McMaster Bujold | antagonist/institutional gatekeeper |
| Simon Kautzsch — Pierre Menard, Author of the Quixote | Pierre Menard, Author of the Quixote | Jorge Luis Borges | receiver |
| Simon Levin — The Uplift War | The Uplift War | David Brin | Neo-chimpanzee soldier |
| Simon Merrill — Sexplosion | Sexplosion | Stanislaw Lem | Author |
| Sïmurgh(King of the Birds, thirty birds) — The Approach to Al-Mu'tasim | The Approach to Al-Mu'tasim | Jorge Luis Borges | Mythical Entity |
| Singalu(PN Singalu) — The Snow Queen | The Snow Queen | Joan D. Vinge | Minor / political figure |
| Sir Donald Acker — Non Serviam | Non Serviam | Stanislaw Lem | Referenced authority |
| Sir Francis — The Windup Girl | The Windup Girl | Paolo Bacigalupi | Bar owner of Sir Francis Drake's |
| Sir Godfrey Kingsman(the elderly gentleman) — Blackout/All Clear | Blackout/All Clear | Connie Willis | Shelter regular / actor |
| Sir Henry(City Remembrancer, the tall man in the black hat) — The Peripheral | The Peripheral | William Gibson | Antagonist |
| Sir Philip Potter(Philip Potter, Sir Philip) — Queen of the States | Queen of the States | Lisa Goldstein | Unwitting helper |
| Siri — Echopraxia | Echopraxia | Peter Watts | Moore's son |
| Siri — Hyperion | Hyperion | Dan Simmons | actantial:sender |
| Siri Keeton(Siri, Pod-man, commissar +6) — Blindsight | Blindsight | Peter Watts | Subject of hemispherectomy |
| Siri Keeton — Echopraxia | Echopraxia | Peter Watts | Transmitter |
| Siri's Father(Dad) — Blindsight | Blindsight | Peter Watts | Parent |
| Sirix(Sirix Odela) — Ancillary Sword | Ancillary Sword | Ann Leckie | Samirend intermediary / Undergarden resident |
| Siro — The Dispossessed | The Dispossessed | Ursula K. Le Guin | Rebel |
| Sirus(First Secretary, Temmon Ashwini Sirus, First Secretary Sirus) — The Snow Queen | The Snow Queen | Joan D. Vinge | Hegemonic Assembly figurehead, Prime Minister's natural son |
| Sisela Ytheleus 1/2 — Excession | Excession | Iain M. Banks | Drone |
| Sister Carmody — Blackout/All Clear | Blackout/All Clear | Connie Willis | Supporting / nurse |
| Sister Duscha(Duscha) — Chasm City | Chasm City | Alastair Reynolds | Neurological specialist |
| Sister Gabriel — Blackout/All Clear | Blackout/All Clear | Connie Willis | Supporting / nurse |
| Sister Helene — A Canticle for Leibowitz | A Canticle for Leibowitz | Walter M. Miller, Jr. | minor |
| Sister Marjorie — Take Back Plenty | Take Back Plenty | Colin Greenland | opponent |
| Sister Veronica — Take Back Plenty | Take Back Plenty | Colin Greenland | opponent |
| Six Capsaicin — A Desolation Called Peace | A Desolation Called Peace | Arkady Martine | Ship captain, minor |
| Six Rainfall — A Desolation Called Peace | A Desolation Called Peace | Arkady Martine | Ship's doctor or medical researcher |
| Sixteen Moonrise(Fleet Captain, Fleet Captain Sixteen Moonrise, Ascent +1) — A Desolation Called Peace | A Desolation Called Peace | Arkady Martine | Fleet Captain, Twenty-Fourth Legion; internal antagonist |
| Skaaiat Awer(Inspector Supervisor Skaaiat, then-Lieutenant Skaaiat) — Ancillary Justice | Ancillary Justice | Ann Leckie | helper/authority |
| Skaaiat Awer(Inspector Supervisor) — Ancillary Sword | Ancillary Sword | Ann Leckie | Inspector Supervisor |
| Skaffen-Amtiskaw(drone) — Use of Weapons | Use of Weapons | Iain M. Banks | Culture drone |
| Skinner(Skinner-san) — Virtual Light | Virtual Light | William Gibson | Original bridge resident |
| Skipper(respectable skipper) — The Fifth Sally or The Mischief of King Balerion | The Fifth Sally or The Mischief of King Balerion | Stanislaw Lem | Merchant fleet owner |
| Sky Haussmann(Titus, Sky) — Chasm City | Chasm City | Alastair Reynolds | Historical figure and child on the Santiago |
| Slake-moths(The five, winged things, the slake-moth +4) — Perdido Street Station | Perdido Street Station | China Miéville | Multidimensional predators |
| Slawek — The Ministry for the Future | The Ministry for the Future | Kim Stanley Robinson | Glaciologist |
| Sleeper Service(Quietly Confident, avatar) — Excession | Excession | Iain M. Banks | Eccentric GSV |
| Slick Henry(Slick) — Mona Lisa Overdrive | Mona Lisa Overdrive | William Gibson | Mechanic and artist |
| Slim Lemke(Moses Lemke Stone) — The Moon Is a Harsh Mistress | The Moon Is a Harsh Mistress | Robert A. Heinlein | Minor revolutionary fellow-traveler |
| Slose — The Left Hand of Darkness | The Left Hand of Darkness | Ursula K. Le Guin | Commensal politician |
| Slusinski — Blue Mars | Blue Mars | Kim Stanley Robinson | actantial:helper |
| Slysz — A Perfect Vacuum | A Perfect Vacuum | Stanislaw Lem | Theorist |
| Small Maxa(Maxa, Mother Dyeth) — Stars in My Pocket Like Grains of Sand | Stars in My Pocket Like Grains of Sand | Samuel R. Delany | Family Member |
| Smith — Neuromancer | Neuromancer | William Gibson | Art dealer / fence |
| Snake(healer, Snake-child, healer-child +1) — Dreamsnake | Dreamsnake | Vonda N. McIntyre | protagonist |
| Snibbins — A Perfect Vacuum | A Perfect Vacuum | Stanislaw Lem | Servant |
| Snibbins — Les Robinsonades | Les Robinsonades | Stanislaw Lem | Imaginary Servant |
| Snim Asj(Snim) — The Demolished Man | The Demolished Man | Alfred Bester | Minor criminal |
| Sniper — Perhaps the Stars | Perhaps the Stars | Ada Palmer | Captive / Resistance Leader |
| Sniper(Thirteenth O.S., O.S., Ojiro Sniper) — The Will to Battle | The Will to Battle | Ada Palmer | Assassin, enemy of J.E.D.D. Mason |
| Sniper — Too Like the Lightning | Too Like the Lightning | Ada Palmer | Celebrity / Actor |
| Snow(Ratface, little man, Dr. Snow) — Solaris | Solaris | Stanislaw Lem | Exhausted Station crew member |
| Sofia Mendes(Mendes, Sofia) — The Sparrow | The Sparrow | Mary Doria Russell | AI analyst contracted to ISAS |
| Sol Weintraub(the Wandering Jew (reputation)) — Hyperion | Hyperion | Dan Simmons | Object of quest / afflicted child |
| Sol Weintraub(Rachel, Moneta, Sol +1) — The Fall of Hyperion | The Fall of Hyperion | Dan Simmons | Pilgrim; scholar caring for infant Rachel |
| Solange Marriot(Mme Solange Marriot, Mme Solange, authoress) — Rien du tout, ou la consequence | Rien du tout, ou la consequence | Stanislaw Lem | Author |
| Somchai — The Windup Girl | The Windup Girl | Paolo Bacigalupi | Jaidee's companion / minor character |
| Somdet Chaopraya(Queen's Protector, Protector) — The Windup Girl | The Windup Girl | Paolo Bacigalupi | Senior Thai nobleman |
| Sophie(Alyx) — Lost Futures | Lost Futures | Lisa Tuttle | Clare's closest friend |
| Sordso(Prince Sordso, Sordso the Sot) — Paladin of Souls | Paladin of Souls | Lois McMaster Bujold | antagonist/subordinate |
| Southwest miners' delegate(thin, small, middle-aged man) — The Dispossessed | The Dispossessed | Ursula K. Le Guin | Visiting PDC delegate |
| Sov — The Left Hand of Darkness | The Left Hand of Darkness | Ursula K. Le Guin | narrator (appended story) |
| Spade — The Yiddish Policemen's Union | The Yiddish Policemen's Union | Michael Chabon | Opponent / federal overseer |
| Spain — Seven Surrenders | Seven Surrenders | Ada Palmer | Leader |
| Speaker Gibbons(Gabriel) — The Fall of Hyperion | The Fall of Hyperion | Dan Simmons | Speaker of the All Thing |
| Speaker Jin Im-Jin(Jin Im-Jin, Speaker) — Perhaps the Stars | Perhaps the Stars | Ada Palmer | Remaker and Triumvir |
| Speedy(SPD-13, SPD models) — I, Robot | I, Robot | Isaac Asimov | actantial:object |
| Spencer — Blue Mars | Blue Mars | Kim Stanley Robinson | Sax's associate, resistance member |
| Spencer(Spencer Jackson) — Red Mars | Red Mars | Kim Stanley Robinson | Resistance operative, atmospheric scientist associate |
| Spencer Jackson(Spencer, Steve) — Green Mars | Green Mars | Kim Stanley Robinson | First Hundred engineer; underground operative |
| Spender(Jeff Spender, The Lonely One) — The Martian Chronicles | The Martian Chronicles | Ray Bradbury | Crew / rogue killer, Fourth Expedition |
| Spenser Reynolds — The Fall of Hyperion | The Fall of Hyperion | Dan Simmons | Artist / provocateur |
| Spiro — The Yiddish Policemen's Union | The Yiddish Policemen's Union | Michael Chabon | helper |
| Squeaky — Snow Crash | Snow Crash | Neal Stephenson | helper |
| Sreekah-pol — Startide Rising | Startide Rising | David Brin | Stenos neo-dolphin / Takkata-Jim's operative |
| Staban Tuek — Dune | Dune | Frank Herbert | actantial:helper / sender |
| Stahnyn — The Stone Sky | The Stone Sky | N. K. Jemisin | minor antagonist/gatekeeper |
| Stan Leweski — The Fall of Hyperion | The Fall of Hyperion | Dan Simmons | Innkeeper of Cicero's |
| Station Administrator — Stars in My Pocket Like Grains of Sand | Stars in My Pocket Like Grains of Sand | Samuel R. Delany | Administrator |
| Station Administrator Celar — Ancillary Sword | Ancillary Sword | Ann Leckie | Station administrator |
| Stavin — Dreamsnake | Dreamsnake | Vonda N. McIntyre | patient |
| Steel(Mr. Steel, Lord Steel, Flenser +3) — A Fire Upon the Deep | A Fire Upon the Deep | Vernor Vinge | antagonist / actantial opponent |
| Steel(Remwha, Gray Man) — The Stone Sky | The Stone Sky | N. K. Jemisin | Stone eater / original tuner / antagonist |
| Steely Glint — Excession | Excession | Iain M. Banks | GCV |
| Stefan — Fledgling | Fledgling | Octavia E. Butler | Shori's Ina brother |
| Stefan — New York 2140 | New York 2140 | Kim Stanley Robinson | Skimboarder |
| Stella Volkova(Stella) — Pattern Recognition | Pattern Recognition | William Gibson | Contact and twin of the maker |
| Stem-Fulcher — Perdido Street Station | Perdido Street Station | China Miéville | Associate of Rudgutter |
| Stephen Albert(Albert) — The Circular Ruins | The Circular Ruins | Jorge Luis Borges | Sinologist |
| Stephen Albert — The Form of the Sword | The Form of the Sword | Jorge Luis Borges | Sinologist, former missionary |
| Stephen Byerley(Byerley, Steve, the Co-ordinator +1) — I, Robot | I, Robot | Isaac Asimov | District attorney; mayor; World Co-ordinator; suspected robot |
| Stern — Cyteen | Cyteen | C. J. Cherryh | Investigator from Moreyville |
| Stets(VC billionaire boy) — Agency | Agency | William Gibson | Tech backer |
| Stetson Parker(Colonel Parker) — The Calculating Stars | The Calculating Stars | Mary Robinette Kowal | antagonist |
| Stettin(Stettin Palver) — The Foundation Trilogy | The Foundation Trilogy | Isaac Asimov | mentalic leader / Wanda's husband |
| Steve — Blue Mars | Blue Mars | Kim Stanley Robinson | Rebel engineer |
| Steve Dawson — The Coral Bones | The Coral Bones | Jynne Martin | Minor antagonist |
| Stilgar(Stil) — Dune | Dune | Frank Herbert | actantial:helper / donor |
| Stod Perice — Use of Weapons | Use of Weapons | Iain M. Banks | Medic |
| Stone eater woman — The Fifth Season | The Fifth Season | N.K. Jemisin | Companion to the man |
| stoop-colonel — The Uplift War | The Uplift War | David Brin | Gubru Talon Soldier officer |
| Stor Gendibal(Speaker Gendibal, Master, Gendibal +3) — Foundation's Edge | Foundation's Edge | Isaac Asimov | Speaker of the Second Foundation |
| storekeeper(store-keeper) — The South | The South | Jorge Luis Borges | minor |
| Stormgren(Rikki, Secretary-General) — Childhood's End | Childhood's End | Arthur C. Clarke | UN Secretary-General, humanity's intermediary with Karellen |
| Strake — Lord of Light | Lord of Light | Roger Zelazny | Retainer |
| Stranger(the ring, Synchronicus/Symphonicus) — Tale of the Three Storytelling Machines of King Genius | Tale of the Three Storytelling Machines of King Genius | Stanislaw Lem | Emissary |
| Stratton(Robert, Mr. Stratton) — Stories of Your Life and Others | Stories of Your Life and Others | Ted Chiang | Nomenclator |
| Strigan(Arilesperas Strigan) — Ancillary Justice | Ancillary Justice | Ann Leckie | Exile doctor / reluctant donor |
| Stu(Stuart LaJoie, Lord Stuart, Comte LaJoie +1) — The Moon Is a Harsh Mistress | The Moon Is a Harsh Mistress | Robert A. Heinlein | Earthside sympathizer and recruit |
| Stuart Gratton(Harry, the baby, the boy) — The Separation | The Separation | Christopher Priest | Historian and oral history author; frame narrator |
| Stuart Gust — Exhalation | Exhalation | Ted Chiang | Forum user |
| Stuart Gust(Stuart) — The Lifecycle of Software Objects | The Lifecycle of Software Objects | Ted Chiang | User-group member |
| Styrka — Speaker for the Dead | Speaker for the Dead | Orson Scott Card | Student |
| Su — New York 2140 | New York 2140 | Kim Stanley Robinson | Boathouse worker |
| Su-Hyeon(Jung Su-Hyeon, Censor, Jung Su-Hyeon Ancelet Kosala +2) — Perhaps the Stars | Perhaps the Stars | Ada Palmer | Former Censor and current volunteer coordinator |
| Su-Hyeon — Too Like the Lightning | Too Like the Lightning | Ada Palmer | Deputy to the Censor |
| Sub-major Stott — The Forever War | The Forever War | Joe Haldeman | company commander |
| Sublett — Virtual Light | Virtual Light | William Gibson | Fugitive's companion |
| Subtillion(the Cybernerian, Lord High Thaumaturge and Apothecary to the Throne) — Tale of the Three Storytelling Machines of King Genius | Tale of the Three Storytelling Machines of King Genius | Stanislaw Lem | Mental Engineer and Saboteur |
| Subtillion — The Cyberiad | The Cyberiad | Stanislaw Lem | Cybernerian / Mental engineer |
| Sudjic — Revelation Space | Revelation Space | Alastair Reynolds | Ultra crew member |
| Suessi(Hannes) — Startide Rising | Startide Rising | David Brin | Human engineer aboard the skiff |
| Sugaiguntung(Professor Doctor, Professor Dr. Sugaiguntung, Professor Doctor Sugaiguntung +1) — Stand on Zanzibar | Stand on Zanzibar | John Brunner | Defector / Object of Extraction |
| Sugi Yoshida(Redwood) — Perhaps the Stars | Perhaps the Stars | Ada Palmer | Local tyrant / Camp commander |
| Sugimoto — The Evolution of Human Science | The Evolution of Human Science | Ted Chiang | Inventor / Scientist |
| Sukey(Wututu, Mary, Daisy +1) — American Gods | American Gods | Neil Gaiman | historical interlude protagonist |
| Sultan Mawji Darya — The Years of Rice and Salt | The Years of Rice and Salt | Kim Stanley Robinson | Supporting / sender |
| Sultana Katima(the Sultana) — The Years of Rice and Salt | The Years of Rice and Salt | Kim Stanley Robinson | Co-ruler, authority figure |
| Sumo boy — All Tomorrow's Parties | All Tomorrow's Parties | William Gibson | Store clerk |
| Sung — Red Mars | Red Mars | Kim Stanley Robinson | actantial:receiver |
| Sunni(Ms Haseem, Sunni Haseem, Sunni-ma'am +1) — Air | Air | Geoff Ryman | Creditor / antagonist |
| Supaari VaGayjur(Supaari) — The Sparrow | The Sparrow | Mary Doria Russell | Jana'ata merchant, alien interlocutor |
| Suppeh — Startide Rising | Startide Rising | David Brin | Ship's purser |
| Supreme Bishop Digby(Reverend Doctor Daniel Digby, Digby, Junior +1) — Stranger in a Strange Land | Stranger in a Strange Land | Robert A. Heinlein | Minor / Institutional figure |
| Supreme Bishop Short — Stranger in a Strange Land | Stranger in a Strange Land | Robert A. Heinlein | actantial:opponent |
| Sura Novi(Sura, Novi, Suranoviremblastiran) — Foundation's Edge | Foundation's Edge | Isaac Asimov | Hamishwoman, Gendibal's companion and mentalic sensor |
| Surgeon Kouska(army doctor, doctor-prisoner Kouska, young surgeon Kouska +2) — De Impossibilitate Vitae / De Impossibilitate Prognoscendi | De Impossibilitate Vitae / De Impossibilitate Prognoscendi | Stanislaw Lem | Professor Kouska's father |
| Suriyawong(Suri) — Ender's Game | Ender's Game | Orson Scott Card | Military second-in-command / ambiguous loyalist |
| Susan Calvin(Dr. Calvin, Miss Susan, Susan) — I, Robot | I, Robot | Isaac Asimov | Robopsychologist; investigator; expositor |
| Susan James(James, Suze, The Gang of Four +6) — Blindsight | Blindsight | Peter Watts | Secondary persona of Susan James |
| Susie Hereira(Gunner Third Susanna Hereira) — Gateway | Gateway | Frederik Pohl | Minor/Memory figure |
| Sutcliffe(Sut) — Count Zero | Count Zero | William Gibson | Point man / Mercenary |
| Suzanne — Acceptance | Acceptance | Jeff VanderMeer | Séance & Science Brigade Member |
| Suzerain of Cost and Caution(the bureaucrat) — The Uplift War | The Uplift War | David Brin | antagonist/Gubru bureaucratic commander |
| Suzerain of Propriety(the priest, the Suzerain) — The Uplift War | The Uplift War | David Brin | Gubru co-commander (triumvirate), high priest |
| Svetlana Barseghian(Svieta, Svetlana) — Pushing Ice | Pushing Ice | Alastair Reynolds | Engineer |
| Svobodov — Virtual Light | Virtual Light | William Gibson | Homicide Cop / Enforcer |
| Swan(Ms. Stockholm) — 2312 | 2312 | Kim Stanley Robinson | Protagonist / Spacer |
| Swift — Dreamsnake | Dreamsnake | Vonda N. McIntyre | object / gift |
| Sword of Atagaris(Ship) — Ancillary Sword | Ancillary Sword | Ann Leckie | Ancillary-crewed ship / antagonist instrument |
| Sydney/Eureka(the set-set) — Seven Surrenders | Seven Surrenders | Ada Palmer | Set-set / Member of Saneer-Weeksbooth |
| Sylvia — Gateway | Gateway | Frederik Pohl | jung:shadow |
| Sylvia (Auntie Syl)(Auntie Syl) — Among Others | Among Others | Jo Walton | ancestor / exposition figure |
| Sylvie — The Uplift War | The Uplift War | David Brin | Chim informant / Fiben's companion |
| Sylvie Jeppson(Sylvie) — Pattern Recognition | Pattern Recognition | William Gibson | Blue Ant employee |
| Syme — 1984 | 1984 | George Orwell | secondary character |
| Szydlowska — The Forever War | The Forever War | Joe Haldeman | Crew member/helper |
| T.J. — To Say Nothing of the Dog | To Say Nothing of the Dog | Connie Willis | Oxford technician/researcher |
| T.J. Lewis — To Say Nothing of the Dog | To Say Nothing of the Dog | Connie Willis | Helper/exposition |
| T.S. Eliot(Eliot) — The Approach to Al-Mu'tasim | The Approach to Al-Mu'tasim | Jorge Luis Borges | Critic / Poet |
| T'orre Na — Ammonite | Ammonite | Nicola Griffith | helper |
| T'sung(Papa T'sung) — The Demolished Man | The Demolished Man | Alfred Bester | actantial:sender |
| Taahira — The Merchant and the Alchemist's Gate | The Merchant and the Alchemist's Gate | Ted Chiang | Ajib's wife |
| Tabitha Jute(Captain Jute, Tabs, Captain +1) — Take Back Plenty | Take Back Plenty | Colin Greenland | Protagonist, captain of the Alice Liddell |
| Tacitus — The Sect of the Phoenix | The Sect of the Phoenix | Jorge Luis Borges | Ancient historian (cited and implicitly criticized) |
| Tacoma Raeburn(Tacoma, Clovis, hot nurse) — The Peripheral | The Peripheral | William Gibson | Security Operative / Paramedic |
| Tadeo Isidoro Cruz(Cruz) — Tlön, Uqbar, Orbis Tertius | Tlön, Uqbar, Orbis Tertius | Jorge Luis Borges | Sergeant |
| Tak — A Closed and Common Orbit | A Closed and Common Orbit | Becky Chambers | helper |
| Tak(Tak of the Archives, Tak of the Bright Spear) — Lord of Light | Lord of Light | Roger Zelazny | Helper / Companion |
| Takayuchi(Taki) — Pattern Recognition | Pattern Recognition | William Gibson | Informant |
| Takkata-Jim(Vice-Captain) — Startide Rising | Startide Rising | David Brin | Mutineer / former executive officer |
| Takver(Tak) — The Dispossessed | The Dispossessed | Ursula K. Le Guin | Biologist and Shevek's partner |
| Tal(the bird, the parrot, Paraclete Pete) — Take Back Plenty | Take Back Plenty | Colin Greenland | Sapient parrot, Contraband member |
| Talbot — Blackout/All Clear | Blackout/All Clear | Connie Willis | FANY colleague |
| Talibe — Use of Weapons | Use of Weapons | Iain M. Banks | Nurse |
| Tamera Lyons — Liking What You See: A Documentary | Liking What You See: A Documentary | Ted Chiang | 1st-year student at Pembleton |
| Tamera Lyons — Stories of Your Life and Others | Stories of Your Life and Others | Ted Chiang | Student narrator |
| Tammer — A Perfect Vacuum | A Perfect Vacuum | Stanislaw Lem | Creator of computer simulation |
| Tandu Stalker(Stalker) — Startide Rising | Startide Rising | David Brin | Tandu commander |
| Tanna — Blue Mars | Blue Mars | Kim Stanley Robinson | Polynesian community member |
| Tanna — Green Mars | Green Mars | Kim Stanley Robinson | supporting |
| Tanner Mirabel(Tanner, slush puppy, hero of Nueva Valparaiso) — Chasm City | Chasm City | Alastair Reynolds | Narrator and patient |
| Tanninger — Timescape | Timescape | Gregory Benford | minor |
| Tansell — Perdido Street Station | Perdido Street Station | China Miéville | Mercenary adventurer and thaumaturge |
| Tapia(Paredes) — The Circular Ruins | The Circular Ruins | Jorge Luis Borges | Troublemaker |
| Taraka(Binder's host, mightiest of the Rakasha, Lord of Hellwell) — Lord of Light | Lord of Light | Roger Zelazny | helper / ambiguous ally |
| Target One — Network Effect | Network Effect | Martha Wells | Antagonist / gray-skinned intruder |
| Target Three — Network Effect | Network Effect | Martha Wells | Antagonist / gray-skinned intruder |
| Target Two — Network Effect | Network Effect | Martha Wells | Antagonist / gray-skinned intruder |
| TargetContact — Network Effect | Network Effect | Martha Wells | opponent |
| Tarko — Take Back Plenty | Take Back Plenty | Colin Greenland | opponent |
| Taryd Roh — The Snow Queen | The Snow Queen | Joan D. Vinge | Antagonist, nomad predator |
| Taskin Cerush(Task, Ms. Cerush) — The City & The City | The City & The City | China Miéville | Admin pool staff |
| Tate — Dawn | Dawn | Octavia E. Butler | Human survivor |
| Tate(Tate Rinaldi) — Imago | Imago | Octavia E. Butler | Human survivor |
| Tate Rinaldi(Tate, Gabe) — Adulthood Rites | Adulthood Rites | Octavia E. Butler | Resister in Phoenix |
| Taudlitz(King Louis, the monarch-Gruppenführer) — A Perfect Vacuum | A Perfect Vacuum | Stanislaw Lem | Monarch / Former SS Officer |
| Teacher Shen(Mr Shen, Shen, Shen Yoh) — Air | Air | Geoff Ryman | opponent-turned-neutral |
| Teafortwo — Perdido Street Station | Perdido Street Station | China Miéville | Wyrman errand runner |
| Tecarnos(Dropping Oil) — The Years of Rice and Salt | The Years of Rice and Salt | Kim Stanley Robinson | minor |
| Technical Boy(the fat kid, Internet) — American Gods | American Gods | Neil Gaiman | actantial:opponent |
| Ted Burrage(Ted) — The Separation | The Separation | Christopher Priest | Front gunner aboard the Wellington bomber |
| Ted Hendrick(Ted) — Starship Troopers | Starship Troopers | Robert A. Heinlein | Trainee / cautionary figure |
| Tediin — Dawn | Dawn | Octavia E. Butler | Oankali female |
| Tediin(Kaaljdahyatediin lel Kahguyaht aj Dinso) — Imago | Imago | Octavia E. Butler | Oankali female |
| Teela Brown(the protector) — Ringworld | Ringworld | Larry Niven | opponent |
| Tehkorahs — Imago | Imago | Octavia E. Butler | Ooloi |
| Telma(Telma Velasco) — The Coral Bones | The Coral Bones | Jynne Martin | Third-strand protagonist |
| Temur(Temur the Lame, the Khan) — The Years of Rice and Salt | The Years of Rice and Salt | Kim Stanley Robinson | opponent |
| Tenenboym — The Yiddish Policemen's Union | The Yiddish Policemen's Union | Michael Chabon | witness/minor |
| Teng — Ammonite | Ammonite | Nicola Griffith | Danner's deputy |
| Teodelina Villar — Tlön, Uqbar, Orbis Tertius | Tlön, Uqbar, Orbis Tertius | Jorge Luis Borges | Socialite |
| Terence St. Trewes(Mr. St. Trewes) — To Say Nothing of the Dog | To Say Nothing of the Dog | Connie Willis | Victorian gentleman, Tossie's eventual fiancé |
| Terrazas(Estevan Terrazas) — The Calculating Stars | The Calculating Stars | Mary Robinette Kowal | helper |
| Terry Lugli — Too Like the Lightning | Too Like the Lightning | Ada Palmer | Actor |
| Terzol — The Dispossessed | The Dispossessed | Ursula K. Le Guin | Dormitory big sister |
| Tess — The Coral Bones | The Coral Bones | Jynne Martin | Hana's partner (addressee) |
| Tessa(Blonde bitch) — All Tomorrow's Parties | All Tomorrow's Parties | William Gibson | Filmmaker/Student |
| TessraBarde(Sergeant) — The Snow Queen | The Snow Queen | Joan D. Vinge | Hegemonic Police sergeant at starport |
| Tethesh — A Closed and Common Orbit | A Closed and Common Orbit | Becky Chambers | minor/exposition |
| Tetrarch of Galilee — Death and the Compass | Death and the Compass | Jorge Luis Borges | Hotel guest |
| Thacker — The City & The City | The City & The City | China Miéville | Official liaison/placater |
| Thad — Dreamsnake | Dreamsnake | Vonda N. McIntyre | helper |
| Thanthalteresco(the Inspector) — Childhood's End | Childhood's End | Arthur C. Clarke | Overlord visitor |
| The Adviser(Adviser, unwitting tool) — The Cyberiad | The Cyberiad | Stanislaw Lem | Artificial intelligence / Royal favorite |
| The Afflicted One — Tlön, Uqbar, Orbis Tertius | Tlön, Uqbar, Orbis Tertius | Jorge Luis Borges | Tyrant/King |
| The Anonymoid — The Sixth Sally or How Trurl and Klapaucius Created a Demon | The Sixth Sally or How Trurl and Klapaucius Created a Demon | Stanislaw Lem | Mythological pirate and mage |
| The anthropologist — Annihilation | Annihilation | Jeff VanderMeer | Expedition member |
| The Assassin(the man, assailant) — Seventy-Two Letters | Seventy-Two Letters | Ted Chiang | Assassin/Thief |
| The Baroness de Bacourt — Pierre Menard, Author of the Quixote | Pierre Menard, Author of the Quixote | Jorge Luis Borges | helper |
| The Bastard — Paladin of Souls | Paladin of Souls | Lois McMaster Bujold | sender |
| The Beast — The Cyberiad | The Cyberiad | Stanislaw Lem | Manufactured Quarry |
| The Beast(pseudoconstabulary beast, three policemen) — The Second Sally or The Offer of King Krool | The Second Sally or The Offer of King Krool | Stanislaw Lem | Cybernetic Construct |
| The Big Man — Count Zero | Count Zero | William Gibson | Mysterious interrogator |
| The biologist(Little Flame, ghost bird, the old biologist +1) — Annihilation | Annihilation | Jeff VanderMeer | Narrator and expedition member |
| The Biologist(I) — Acceptance | Acceptance | Jeff VanderMeer | Survivor in Area X |
| The Biologist(Ghost Bird) — Authority | Authority | Jeff VanderMeer | 12th Expedition Survivor / Returnee |
| The Bishop — Hyperion | Hyperion | Dan Simmons | Shrike Church hierarch/opponent |
| The Black Man — The End | The End | Jorge Luis Borges | Antagonist / avenger |
| The Blight / The Perversion / Newborn Power(newborn, new Power) — A Fire Upon the Deep | A Fire Upon the Deep | Vernor Vinge | antagonist |
| The Book Man(Him) — The Library of Babel | The Library of Babel | Jorge Luis Borges | Mythological figure |
| The Boy — The End | The End | Jorge Luis Borges | Minor figure |
| The Brain — I, Robot | I, Robot | Isaac Asimov | Positronic supercomputer, U.S. Robots |
| The Brown Woman — Queen of the States | Queen of the States | Lisa Goldstein | Actantial sender / faerie summons |
| The Caliph(Commander of the Faithful, Your Majesty) — The Merchant and the Alchemist's Gate | The Merchant and the Alchemist's Gate | Ted Chiang | Royal auditor |
| The Captain — Blindsight | Blindsight | Peter Watts | Ship AI |
| The chief of one of the upper hexagons — The Library of Babel | The Library of Babel | Jorge Luis Borges | Historical librarian |
| The clerk(bishop's clerk) — Doomsday Book | Doomsday Book | Connie Willis | secondary |
| The Clerk — Perdido Street Station | Perdido Street Station | China Miéville | Parliament employee |
| The Colonel — Stand on Zanzibar | Stand on Zanzibar | John Brunner | Military authority / eptification officer |
| The Comet(lady comet) — The Fifth Sally (A) or Trurl's Prescription | The Fifth Sally (A) or Trurl's Prescription | Stanislaw Lem | Antagonist |
| The Commissioner(Police Commander, chief commander of the harbor patrol) — The Fifth Sally or The Mischief of King Balerion | The Fifth Sally or The Mischief of King Balerion | Stanislaw Lem | Police Commander |
| The Commodore — The Forever War | The Forever War | Joe Haldeman | commanding officer |
| The Company — The Lottery in Babylon | The Lottery in Babylon | Jorge Luis Borges | Omnipotent organization |
| The Consul(Merin (implied), Merin) — Hyperion | Hyperion | Dan Simmons | Frame narrator / diplomat pilgrim |
| The Consul — The Fall of Hyperion | The Fall of Hyperion | Dan Simmons | Pilgrim; diplomat and spy for the Ousters |
| The Corpse-robber(filthy man, thief) — The Approach to Al-Mu'tasim | The Approach to Al-Mu'tasim | Jorge Luis Borges | Thief |
| The Countess de Bagnoregio(countess de Bagnoregio) — Pierre Menard, Author of the Quixote | Pierre Menard, Author of the Quixote | Jorge Luis Borges | helper |
| The courier — Virtual Light | Virtual Light | William Gibson | Courier carrying valuable data-glasses |
| The Crawler — Annihilation | Annihilation | Jeff VanderMeer | Unknown entity |
| The Crazy(crazy) — Dreamsnake | Dreamsnake | Vonda N. McIntyre | Guide/antagonist-adjacent |
| The Critic(Narrator, Reviewer) — A Perfect Vacuum (self-review) | A Perfect Vacuum (self-review) | Stanislaw Lem | Reviewer |
| The Daughter(You) — Story of Your Life | Story of Your Life | Ted Chiang | Addressee |
| The Director(Cynthia, Gloria, you) — Acceptance | Acceptance | Jeff VanderMeer | Director of the Southern Reach |
| The Doctor — The Handmaid's Tale | The Handmaid's Tale | Margaret Atwood | Physician at Offred's examination |
| The Dominican Messenger(the Black Friar, Ecce Inquisitor Curiae) — A Canticle for Leibowitz | A Canticle for Leibowitz | Walter M. Miller, Jr. | helper/sender |
| The Duke of Turing — The Diamond Age | The Diamond Age | Neal Stephenson | Mechanical antagonist/donor (Primer) |
| The Dung Lord — The Windup Girl | The Windup Girl | Paolo Bacigalupi | Yellow card crime lord |
| The elderly lady(The hero's daughter) — Tlön, Uqbar, Orbis Tertius | Tlön, Uqbar, Orbis Tertius | Jorge Luis Borges | Historical figure / Victim |
| The Electroknight(magnate, imposing personage, Grand Seneschal and Artifactotum to the King +1) — The Fourth Sally or How Trurl Built a Femfatalatron | The Fourth Sally or How Trurl Built a Femfatalatron | Stanislaw Lem | Royal emissary |
| The Electronic Bard(the machine) — The Cyberiad | The Cyberiad | Stanislaw Lem | Artificial intelligence |
| The Electronic Bard(electropoet, homeostatic Homer, Greatest Poet in the Universe +2) — The First Sally (A) or Trurl's Electronic Bard | The First Sally (A) or Trurl's Electronic Bard | Stanislaw Lem | Cybernetic poet |
| The Emperor(ruler of the neighboring state of lb) — The Fourth Sally or How Trurl Built a Femfatalatron | The Fourth Sally or How Trurl Built a Femfatalatron | Stanislaw Lem | Enemy ruler |
| The Enforcers — Snow Crash | Snow Crash | Neal Stephenson | opponent |
| The Etruscan — Idoru | Idoru | William Gibson | Walled City Ghost |
| The Explorer — Exhalation | Exhalation | Ted Chiang | Hypothetical addressee |
| The father(Daddy) — Idiota | Idiota | Stanislaw Lem | Parent in Spallanzani's novel |
| The Father(Paul, Mr Paul) — Klara and the Sun | Klara and the Sun | Kazuo Ishiguro | Josie's father |
| The Father of Winter — Paladin of Souls | Paladin of Souls | Lois McMaster Bujold | sender |
| The Finn(Finn) — Neuromancer | Neuromancer | William Gibson | Fence and tech expert |
| The Forger(Mameluke Kardyoch) — Odysseus of Ithaca | Odysseus of Ithaca | Stanislaw Lem | Explorer and Fraudster |
| The Former Director(Cynthia) — Authority | Authority | Jeff VanderMeer | Former Director of the Southern Reach |
| The Frasque(it) — Take Back Plenty | Take Back Plenty | Colin Greenland | opponent |
| The gardener — Idiota | Idiota | Stanislaw Lem | Servant |
| The Gift-giver — Seven Surrenders | Seven Surrenders | Ada Palmer | Kidnapper |
| The Gnostotron(Omniac, Pansophoscope, APOC +3) — Altruizine or A True Account of How Bonhomius the Hermetic Hermit Tried to Bring About Universal Happiness | Altruizine or A True Account of How Bonhomius the Hermetic Hermit Tried to Bring About Universal Happiness | Stanislaw Lem | Simulated H.P.L.D. intelligence |
| The Governess(French mistress) — De Impossibilitate Vitae / De Impossibilitate Prognoscendi | De Impossibilitate Vitae / De Impossibilitate Prognoscendi | Stanislaw Lem | General Prchl's mistress |
| The grandmother — Idiota | Idiota | Stanislaw Lem | The father's ailing mother |
| The Gunman — Fledgling | Fledgling | Octavia E. Butler | Attacker |
| The Hideous Thing(That, nasty thing) — The Fifth Sally (A) or Trurl's Prescription | The Fifth Sally (A) or Trurl's Prescription | Stanislaw Lem | Antagonist |
| The High Priest — Snow Crash | Snow Crash | Neal Stephenson | opponent |
| The Hindmost(the puppeteer, Hindmost) — Ringworld | Ringworld | Larry Niven | actantial sender/opponent |
| The Honest Sailor(good Samaritan, worthy mariner, crewman) — The Fifth Sally or The Mischief of King Balerion | The Fifth Sally or The Mischief of King Balerion | Stanislaw Lem | Mariner |
| The host(Somebody, You) — Tlön, Uqbar, Orbis Tertius | Tlön, Uqbar, Orbis Tertius | Jorge Luis Borges | Man of the future |
| The husband(the ghost) — Annihilation | Annihilation | Jeff VanderMeer | Member of the 11th expedition; medic |
| The Iceman — American Gods | American Gods | Neil Gaiman | minor |
| The idiot child(The Idiot, fourteen-year-old boy) — Idiota | Idiota | Stanislaw Lem | Central character in Spallanzani's novel |
| The IF — Spook Country | Spook Country | William Gibson | Mysterious Target |
| The inquisitors(official searchers) — The Library of Babel | The Library of Babel | Jorge Luis Borges | Official searchers |
| The King — A Good Shellacking | A Good Shellacking | Stanislaw Lem | Minor offstage authority figure |
| The Law Student — The Approach to Al-Mu'tasim | The Approach to Al-Mu'tasim | Jorge Luis Borges | Protagonist |
| The Leader — The Garden of Forking Paths | The Garden of Forking Paths | Jorge Luis Borges | Commander |
| The Levarch — Ammonite | Ammonite | Nicola Griffith | Echraidhe leader |
| The Librarian — Snow Crash | Snow Crash | Neal Stephenson | helper |
| The Librarian — The Secret Miracle | The Secret Miracle | Jorge Luis Borges | Dream figure |
| The Linguist — Acceptance | Acceptance | Jeff VanderMeer | 12th Expedition member |
| The machine — How the World Was Saved | How the World Was Saved | Stanislaw Lem | Artificial creation |
| The Machine — Trurl's Machine | Trurl's Machine | Stanislaw Lem | Antagonist |
| The Machine That Could Do Everything Starting With N(the machine, Gnost., computerized representative of the Highest Poss. Lev. Devel. +1) — The Cyberiad | The Cyberiad | Stanislaw Lem | Artificial intelligence / Entity |
| The Machine to Grant Your Every Wish — A Good Shellacking | A Good Shellacking | Stanislaw Lem | Artifact/vehicle/helper |
| The Mademoiselle — Revelation Space | Revelation Space | Alastair Reynolds | Employer |
| The Mailman — The Fifth Sally (A) or Trurl's Prescription | The Fifth Sally (A) or Trurl's Prescription | Stanislaw Lem | Courier |
| The Major — Blackout/All Clear | Blackout/All Clear | Connie Willis | minor |
| The Major(Major) — Seven Surrenders | Seven Surrenders | Ada Palmer | Commander of the living toys |
| The Major — Too Like the Lightning | Too Like the Lightning | Ada Palmer | Animated toy soldier |
| The man — The Fifth Season | The Fifth Season | N.K. Jemisin | Orogene slave and world-breaker |
| The Man(Assassin) — All Tomorrow's Parties | All Tomorrow's Parties | William Gibson | Lethal predator |
| The Man with Empty Frames — Count Zero | Count Zero | William Gibson | Mysterious interrogator |
| The Marquise — Rien du tout, ou la consequence | Rien du tout, ou la consequence | Stanislaw Lem | Hypothetical character |
| The Martian (shapeshifter)(Tom, Lavinia, the boy +2) — The Martian Chronicles | The Martian Chronicles | Ray Bradbury | actantial:object |
| The masked man(The man with the head of a bull) — Tlön, Uqbar, Orbis Tertius | Tlön, Uqbar, Orbis Tertius | Jorge Luis Borges | Mysterious figure |
| The Mayor — Dreamsnake | Dreamsnake | Vonda N. McIntyre | secondary |
| The Mayor — The Cyberiad | The Cyberiad | Stanislaw Lem | Civic leader |
| The Mayor — Trurl's Machine | Trurl's Machine | Stanislaw Lem | Civic authority |
| The moaning creature — Annihilation | Annihilation | Jeff VanderMeer | Delirium entity |
| The mother(Mommy) — Idiota | Idiota | Stanislaw Lem | Parent in Spallanzani's novel |
| The Mother(Mom, Chrissie, Mrs Arthur +1) — Klara and the Sun | Klara and the Sun | Kazuo Ishiguro | Josie's mother |
| The Mothers — A Closed and Common Orbit | A Closed and Common Orbit | Becky Chambers | opponent |
| The Mouse(Mouse) — Nova | Nova | Samuel R. Delany | Cyborg stud and sensory-syrynx player |
| The Multitudians(natives) — The Cyberiad | The Cyberiad | Stanislaw Lem | Citizens |
| The narrator(Bonhomius) — The Cyberiad | The Cyberiad | Stanislaw Lem | Benefactor |
| The Narrator(I) — An Examination of the Work of Herbert Quain | An Examination of the Work of Herbert Quain | Jorge Luis Borges | Literary friend and retrospective essayist |
| The Narrator(Anatomist) — Exhalation | Exhalation | Ted Chiang | Scientist and author of the engraved account |
| The Narrator(city slicker) — Funes the Memorious | Funes the Memorious | Jorge Luis Borges | Observer/Testifier |
| The Narrator(The Reviewer) — Odysseus of Ithaca | Odysseus of Ithaca | Stanislaw Lem | Literary Critic |
| The Narrator — Pierre Menard, Author of the Quixote | Pierre Menard, Author of the Quixote | Jorge Luis Borges | sender/voice |
| The Narrator(Puerto Rican parrot) — The Great Silence | The Great Silence | Ted Chiang | Speaker and representative of a dying species |
| The Narrator(my father, I) — The Library of Babel | The Library of Babel | Jorge Luis Borges | Aging librarian and author |
| The Narrator — The Lottery in Babylon | The Lottery in Babylon | Jorge Luis Borges | Exile and Former Proconsul/Slave |
| The Narrator — The Sect of the Phoenix | The Sect of the Phoenix | Jorge Luis Borges | First-person scholarly investigator |
| The Narrator — Theme of the Traitor and the Hero | Theme of the Traitor and the Hero | Jorge Luis Borges | Author |
| The Narrator — U-Write-It | U-Write-It | Stanislaw Lem | Cultural critic / Essayist |
| The Narrator(I) — What's Expected of Us | What's Expected of Us | Ted Chiang | Messenger/Observer |
| The narrator of the Library — The Form of the Sword | The Form of the Sword | Jorge Luis Borges | Librarian, traveler |
| The Nemo — Perhaps the Stars | Perhaps the Stars | Ada Palmer | Submarine Commander |
| The New Faerie King — Queen of the States | Queen of the States | Lisa Goldstein | Narrator-figure / twilight king |
| The Nurse(volunteer nurse, society miss, young lady) — De Impossibilitate Vitae / De Impossibilitate Prognoscendi | De Impossibilitate Vitae / De Impossibilitate Prognoscendi | Stanislaw Lem | Professor Kouska's mother |
| The old man(old hermit) — Sexplosion | Sexplosion | Stanislaw Lem | Protagonist |
| The old man(He, himself) — Spook Country | Spook Country | William Gibson | Expert / Mentor |
| The Old Man — A Perfect Vacuum | A Perfect Vacuum | Stanislaw Lem | Survivor/Wanderer |
| The Old Man (Cardboard City) — All Tomorrow's Parties | All Tomorrow's Parties | William Gibson | Homeless inhabitant |
| The paleface — The Cyberiad | The Cyberiad | Stanislaw Lem | Biological entity |
| The Patriarch — The Cyberiad | The Cyberiad | Stanislaw Lem | Dream construct / Sage |
| The Pilgrim(the old man, the wanderer) — A Canticle for Leibowitz | A Canticle for Leibowitz | Walter M. Miller, Jr. | catalyst/helper |
| The poet — The Form of the Sword | The Form of the Sword | Jorge Luis Borges | Slave and poet |
| The Poet(the versifying vagrant) — A Canticle for Leibowitz | A Canticle for Leibowitz | Walter M. Miller, Jr. | jung:trickster |
| The professor — Tlön, Uqbar, Orbis Tertius | Tlön, Uqbar, Orbis Tertius | Jorge Luis Borges | Academic advisor |
| The psychologist — Annihilation | Annihilation | Jeff VanderMeer | Expedition leader |
| The Public Crier — Exhalation | Exhalation | Ted Chiang | District official |
| The Purifiers(fanatics) — The Library of Babel | The Library of Babel | Jorge Luis Borges | Fanatical sect |
| The Queen of the Yahoos — The Form of the Sword | The Form of the Sword | Jorge Luis Borges | Monarch |
| The Rabbit / Mr. Rabbit(Rabbit) — Rainbows End | Rainbows End | Vernor Vinge | trickster |
| The Reader — The Secret Miracle | The Secret Miracle | Jorge Luis Borges | Dream figure |
| The rector — Blackout/All Clear | Blackout/All Clear | Connie Willis | Shelter regular |
| The Regiment Doctor(superior) — De Impossibilitate Vitae / De Impossibilitate Prognoscendi | De Impossibilitate Vitae / De Impossibilitate Prognoscendi | Stanislaw Lem | Surgeon Kouska's superior |
| The Reversalists — Exhalation | Exhalation | Ted Chiang | Sect of mechanicians |
| The Reviewer(I) — De Impossibilitate Vitae / De Impossibilitate Prognoscendi | De Impossibilitate Vitae / De Impossibilitate Prognoscendi | Stanislaw Lem | Narrator |
| The Reviewer(I, we, this reviewer) — Die Kultur als Fehler | Die Kultur als Fehler | Stanislaw Lem | Narrator / Critic |
| The Reviewer(Narrator) — Gigamesh | Gigamesh | Stanislaw Lem | Critic |
| The Reviewer(Narrator) — Idiota | Idiota | Stanislaw Lem | Literary critic |
| The Reviewer(The writer of these words, this reviewer) — Perycalypsis | Perycalypsis | Stanislaw Lem | Narrator and book reviewer |
| The Reviewer(I, we) — Rien du tout, ou la consequence | Rien du tout, ou la consequence | Stanislaw Lem | Literary Critic / Narrator |
| The Robber — A Canticle for Leibowitz | A Canticle for Leibowitz | Walter M. Miller, Jr. | Opponent/Trickster |
| The Rooster — All Tomorrow's Parties | All Tomorrow's Parties | William Gibson | Virtual envoy |
| The Russian(Kombinat man) — Idoru | Idoru | William Gibson | Criminal Enforcer |
| The Saint — The Approach to Al-Mu'tasim | The Approach to Al-Mu'tasim | Jorge Luis Borges | Holy man |
| The scarf — All Tomorrow's Parties | All Tomorrow's Parties | William Gibson | Hitman |
| The Serb(assassin) — De Impossibilitate Vitae / De Impossibilitate Prognoscendi | De Impossibilitate Vitae / De Impossibilitate Prognoscendi | Stanislaw Lem | Historical figure |
| The Sergeant — Take Back Plenty | Take Back Plenty | Colin Greenland | opponent |
| The Sergeant — The Secret Miracle | The Secret Miracle | Jorge Luis Borges | Execution commander |
| The Shark — Air | Air | Geoff Ryman | opponent |
| The Shrike — The Fall of Hyperion | The Fall of Hyperion | Dan Simmons | Antagonist / mythic creature |
| The sorcerer(the taciturn man, the foreigner, the gray man) — The Form of the Sword | The Form of the Sword | Jorge Luis Borges | Dreamer and creator |
| The Source — The Snow Queen | The Snow Queen | Joan D. Vinge | Criminal underworld broker |
| The Starholmer(It, Holmer, Master of the Swarms) — The Fountains of Paradise | The Fountains of Paradise | Arthur C. Clarke | frame narrator |
| The steely bishop of Lund(bishop of Lund) — Three Versions of Judas | Three Versions of Judas | Jorge Luis Borges | Clergyman |
| The Steelypips(mechanics and mechanists) — The Cyberiad | The Cyberiad | Stanislaw Lem | Citizens/Engineers |
| The Steelypips — The Fifth Sally (A) or Trurl's Prescription | The Fifth Sally (A) or Trurl's Prescription | Stanislaw Lem | Inhabitants |
| The steward — Doomsday Book | Doomsday Book | Connie Willis | minor |
| The Stranger(The strange woman, The unknown woman) — Acceptance | Acceptance | Jeff VanderMeer | Unknown trespasser |
| The surveyor — Annihilation | Annihilation | Jeff VanderMeer | Tactical and military member |
| The Suzerain of Beam and Talon(the admiral, the military commander) — The Uplift War | The Uplift War | David Brin | Gubru co-commander (triumvirate), military |
| The taciturn man(the gray man, the foreigner, The sorcerer) — The Circular Ruins | The Circular Ruins | Jorge Luis Borges | Dreamer |
| The taciturn man(The gray man, The sorcerer) — Tlön, Uqbar, Orbis Tertius | Tlön, Uqbar, Orbis Tertius | Jorge Luis Borges | Dreamer |
| The Talent — Air | Air | Geoff Ryman | other |
| The Taxpayer(Pritchard) — The Martian Chronicles | The Martian Chronicles | Ray Bradbury | Minor character / civilian |
| The traveling decipherer — The Library of Babel | The Library of Babel | Jorge Luis Borges | Linguist |
| The unbeloved heroine(unbeloved) — Rien du tout, ou la consequence | Rien du tout, ou la consequence | Stanislaw Lem | Nonexistent protagonist |
| The unnamed narrator(the reporter) — I, Robot | I, Robot | Isaac Asimov | genette_narrative:voice |
| The Verbover Rebbe — The Yiddish Policemen's Union | The Yiddish Policemen's Union | Michael Chabon | actantial:opponent |
| The Vespan driver(the boatwoman) — Take Back Plenty | Take Back Plenty | Colin Greenland | minor |
| The Warden(Mort the Wart) — The Moon Is a Harsh Mistress | The Moon Is a Harsh Mistress | Robert A. Heinlein | Lunar Authority administrator and antagonist |
| The Weaver(dancing mad god, spider-presence, vast spider presence) — Perdido Street Station | Perdido Street Station | China Miéville | Multidimensional entity |
| The widow(The Luster of True Instruction) — The Form of the Sword | The Form of the Sword | Jorge Luis Borges | Pirate leader |
| The Woman(assassin, auxiliary) — Use of Weapons | Use of Weapons | Iain M. Banks | Associate of the plotting man |
| The Yardmaster — Tlön, Uqbar, Orbis Tertius | Tlön, Uqbar, Orbis Tertius | Jorge Luis Borges | Challenger |
| The youth(phantasm, his son) — The Circular Ruins | The Circular Ruins | Jorge Luis Borges | Dreamed creation |
| The youth(the dreamed man, the son, the phantasm) — The Form of the Sword | The Form of the Sword | Jorge Luis Borges | Magical creation |
| Thenike — Ammonite | Ammonite | Nicola Griffith | Viajera; Marghe's partner |
| Theo Lane(Governor-General Theo Lane) — Hyperion | Hyperion | Dan Simmons | Governor-General of Hyperion |
| Theo Lane(Governor-General Lane, Governor-General) — The Fall of Hyperion | The Fall of Hyperion | Dan Simmons | Governor-General, Consul's aide |
| Theodora — Fledgling | Fledgling | Octavia E. Butler | Shori's secondary symbiont |
| Theodore — Blackout/All Clear | Blackout/All Clear | Connie Willis | Supporting / evacuee child |
| Therapist — The Ministry for the Future | The Ministry for the Future | Kim Stanley Robinson | Mental health professional |
| Therem of Estre(Estraven the Traitor) — The Left Hand of Darkness | The Left Hand of Darkness | Ursula K. Le Guin | Legendary figure / ancestor (interpolated tale) |
| Therem of Stok(Stokven) — The Left Hand of Darkness | The Left Hand of Darkness | Ursula K. Le Guin | Legendary figure / ancestor (interpolated tale) |
| Theresa — Ender's Game | Ender's Game | Orson Scott Card | supporting/advisor |
| Thessicher — The Left Hand of Darkness | The Left Hand of Darkness | Ursula K. Le Guin | opponent |
| Theta — Hyperion | Hyperion | Dan Simmons | Bikura member |
| Thiago — Network Effect | Network Effect | Martha Wells | Survey crew member / Mensah's brother's marital partner |
| Thirty Wax-Seal — A Desolation Called Peace | A Desolation Called Peace | Arkady Martine | Captain of Knifepoint's Ninth Blooming |
| Thisbe(Ruin's avatar, the witch) — Perhaps the Stars | Perhaps the Stars | Ada Palmer | Assassin |
| Thisbe(Thisbe Saneer, tick, witch) — The Will to Battle | The Will to Battle | Ada Palmer | O.S. assassin / prisoner |
| Thisbe Saneer(Lesley Juniper Sniper Saneer, Lesley, Thisbe +4) — Too Like the Lightning | Too Like the Lightning | Ada Palmer | Authority figure in the Saneer-Weeksbooth bash' |
| Thom Crabtree(Crabtree, Thom) — Pushing Ice | Pushing Ice | Alastair Reynolds | Taphead / Robot Controller |
| Thomas de Quincey(de Quincey) — Three Versions of Judas | Three Versions of Judas | Jorge Luis Borges | Precursor Writer |
| Thomas Hobbes(Hobbes, friend Thomas) — Perhaps the Stars | Perhaps the Stars | Ada Palmer | Historical philosopher / Resurrected companion |
| Thomas Hobbes(Hobbes's specter) — The Will to Battle | The Will to Battle | Ada Palmer | Philosopher Specter |
| Thomas Kyd(Tom Kyd, Kyd) — Queen of the States | Queen of the States | Lisa Goldstein | Antagonist / betrayer |
| Thomas Nashe(Tom, Tom Nashe, Nashe) — Queen of the States | Queen of the States | Lisa Goldstein | POV character / survivor playwright |
| Thon Taddeo(Thon Taddeo Pfardentrott, the scholar, the thon) — A Canticle for Leibowitz | A Canticle for Leibowitz | Walter M. Miller, Jr. | actantial:opponent / actantial:subject |
| Thone — Use of Weapons | Use of Weapons | Iain M. Banks | Squadron Commanding Officer |
| Thoobing — Foundation's Edge | Foundation's Edge | Isaac Asimov | Foundation Ambassador to Sayshell |
| Thorburn — Stories of Your Life and Others | Stories of Your Life and Others | Ted Chiang | Student |
| Thorpe — Tlön, Uqbar, Orbis Tertius | Tlön, Uqbar, Orbis Tertius | Jorge Luis Borges | Advisor |
| Three Azimuth(Minister of War, butcher of the Nakharese mind) — A Desolation Called Peace | A Desolation Called Peace | Arkady Martine | actantial:sender |
| Three Seagrass(Reed, the envoy, Envoy) — A Desolation Called Peace | A Desolation Called Peace | Arkady Martine | Information Ministry envoy, Third Undersecretary |
| Thufir Hawat(Thufir, Hawat) — Dune | Dune | Frank Herbert | captive mentat strategist |
| Thurman — Forever Peace | Forever Peace | Joe Haldeman | opponent |
| Tibe(Pemmer Harge rem ir Tibe, the King's Ear (new), Lord Tibe) — The Left Hand of Darkness | The Left Hand of Darkness | Ursula K. Le Guin | opponent |
| Tibor Lapham — Take Back Plenty | Take Back Plenty | Colin Greenland | minor |
| Tick — Mona Lisa Overdrive | Mona Lisa Overdrive | William Gibson | Data thief |
| Tifany(Officer Tifany) — Network Effect | Network Effect | Martha Wells | Preservation Station Security officer |
| Tiikuchahk(Ti) — Adulthood Rites | Adulthood Rites | Octavia E. Butler | Akin's nearest sibling |
| Tiikuchahk(Ti) — Imago | Imago | Octavia E. Butler | Construct paired sibling |
| Tillotson — 1984 | 1984 | George Orwell | minor character |
| Timothy(Tim, Timmy) — The Martian Chronicles | The Martian Chronicles | Ray Bradbury | Eldest son / observant child |
| Timothy Huynh(Tim Huynh) — Rainbows End | Rainbows End | Vernor Vinge | other |
| Tino(Augustino Leal) — Adulthood Rites | Adulthood Rites | Octavia E. Butler | Human male in the trade village |
| Tino Leal(Tino, stranger, the man +1) — Imago | Imago | Octavia E. Butler | Human resister turned mate |
| Tirin(Tir) — The Dispossessed | The Dispossessed | Ursula K. Le Guin | Shevek's Friend, Playwright |
| Tirolle('Rolle) — A Fire Upon the Deep | A Fire Upon the Deep | Vernor Vinge | minor/crew |
| Tisarwat(Lieutenant Tisarwat, Anaander Mianaai (fragment)) — Ancillary Sword | Ancillary Sword | Ann Leckie | Junior officer / former Anaander fragment |
| Tito(China, Oshosi, Ramone) — Spook Country | Spook Country | William Gibson | Operative/Courier |
| Tobias — Nova | Nova | Samuel R. Delany | Brother of Lynceos and Idas |
| Tom Castro — Tlön, Uqbar, Orbis Tertius | Tlön, Uqbar, Orbis Tertius | Jorge Luis Borges | Impostor |
| Tom Orley(Thomas Orley, Tom) — Startide Rising | Startide Rising | David Brin | Special operative / gene-crafted human |
| Tomás — Imago | Imago | Octavia E. Butler | Human mate to Jodahs |
| Tomas da Silva(Father General da Silva) — The Sparrow | The Sparrow | Mary Doria Russell | Thirty-first General of the Society of Jesus |
| Tomás Gomez(Tomás) — The Martian Chronicles | The Martian Chronicles | Ray Bradbury | protagonist |
| Tomcat of the Caryatid — Les Robinsonades | Les Robinsonades | Stanislaw Lem | Imaginary Animal |
| Tommie Parker(Professor Thomas Parker, Tommie, Winnie) — Rainbows End | Rainbows End | Vernor Vinge | Helper/Cabal member |
| Tommy(Sweet Boy, sweety gums) — Never Let Me Go | Never Let Me Go | Kazuo Ishiguro | Former Hailsham student and Donor |
| Tommy — The Peripheral | The Peripheral | William Gibson | State Police deputy |
| Tonkee — The Fifth Season | The Fifth Season | N.K. Jemisin | Companion to Essun |
| Tonkee — The Stone Sky | The Stone Sky | N. K. Jemisin | Helper / comic foil |
| Tony — Snow Crash | Snow Crash | Neal Stephenson | opponent |
| Tony — Stand on Zanzibar | Stand on Zanzibar | John Brunner | minder/handler |
| Tony Crane — Hell Is the Absence of God | Hell Is the Absence of God | Ted Chiang | Support group member |
| Tor(Persiponë, Starhiker) — The Snow Queen | The Snow Queen | Joan D. Vinge | Street figure, intermediary |
| Toshi(Toshi onee-san, Acting Censor, Toshi Mitsubishi) — Perhaps the Stars | Perhaps the Stars | Ada Palmer | Technician / Analyst |
| Toshio(Ladder-runner, Sharp-Eyes, Toshio Iwashika) — Startide Rising | Startide Rising | David Brin | Human midshipman / field team member |
| Tossie Mering(Mesiel, Miss Mering, Tocelyn +3) — To Say Nothing of the Dog | To Say Nothing of the Dog | Connie Willis | Victorian daughter/pivot of the incongruity |
| Totilung — Stand on Zanzibar | Stand on Zanzibar | John Brunner | Antagonist / Law Enforcement |
| Toure Bomoko — Dune | Dune | Frank Herbert | President of the Commission of Ecumenical Translators, Zensunni Ulema |
| Tranny — Snow Crash | Snow Crash | Neal Stephenson | helper |
| Translator Dlique(Dlique) — Ancillary Sword | Ancillary Sword | Ann Leckie | Presger Translator / inciting victim |
| Trepil — The Dispossessed | The Dispossessed | Ursula K. Le Guin | PDC member |
| Treviranus(Franz Treviranus) — Death and the Compass | Death and the Compass | Jorge Luis Borges | Police commissioner |
| Treviranus — Tlön, Uqbar, Orbis Tertius | Tlön, Uqbar, Orbis Tertius | Jorge Luis Borges | Police Commissioner |
| Trey(Mr Trey) — Take Back Plenty | Take Back Plenty | Colin Greenland | Eladeldi military agent (flashback) |
| Tribune Natekari(Natekari) — Perhaps the Stars | Perhaps the Stars | Ada Palmer | Blacklaw Tribune |
| Tricarico Palynides — Take Back Plenty | Take Back Plenty | Colin Greenland | secondary |
| Trin — The Foundation Trilogy | The Foundation Trilogy | Isaac Asimov | minor |
| Tristan — The Years of Rice and Salt | The Years of Rice and Salt | Kim Stanley Robinson | Musician, cafe interlocutor |
| Tritch — The Foundation Trilogy | The Foundation Trilogy | Isaac Asimov | ship captain |
| Tritt — The Gods Themselves | The Gods Themselves | Isaac Asimov | Parental triad member |
| Trizivian Huncus(last philosopher of Ninnica) — Tale of the Three Storytelling Machines of King Genius | Tale of the Three Storytelling Machines of King Genius | Stanislaw Lem | Philosopher |
| Trooper Phillipi(the bike-trooper) — Mirror Dance | Mirror Dance | Lois McMaster Bujold | minor soldier |
| Trooper Tonkin — Mirror Dance | Mirror Dance | Lois McMaster Bujold | witness |
| Trot — Blackout/All Clear | Blackout/All Clear | Connie Willis | minor |
| Trurl(Trurl the Magnificent, the real Trurl, the Constructor of the World's Stupidest Computer) — A Good Shellacking | A Good Shellacking | Stanislaw Lem | Constructor, protagonist/foil |
| Trurl(the constructor) — Altruizine or A True Account of How Bonhomius the Hermetic Hermit Tried to Bring About Universal Happiness | Altruizine or A True Account of How Bonhomius the Hermetic Hermit Tried to Bring About Universal Happiness | Stanislaw Lem | Compassionate host and listener |
| Trurl(Trurl the constructor) — How the World Was Saved | How the World Was Saved | Stanislaw Lem | Constructor |
| Trurl(Great Constructor, Fabulous Constructor) — Tale of the Three Storytelling Machines of King Genius | Tale of the Three Storytelling Machines of King Genius | Stanislaw Lem | Constructor and Storyteller |
| Trurl(constructor, foreigner) — The Cyberiad | The Cyberiad | Stanislaw Lem | Constructor and inventor |
| Trurl(the constructor) — The Fifth Sally (A) or Trurl's Prescription | The Fifth Sally (A) or Trurl's Prescription | Stanislaw Lem | Problem-solver |
| Trurl(constructor, pseudo-Trurl) — The Fifth Sally or The Mischief of King Balerion | The Fifth Sally or The Mischief of King Balerion | Stanislaw Lem | Constructor and inventor |
| Trurl(famed constructor, intrepid constructor) — The First Sally (A) or Trurl's Electronic Bard | The First Sally (A) or Trurl's Electronic Bard | Stanislaw Lem | Constructor and protagonist |
| Trurl — The First Sally or The Trap of Gargantius | The First Sally or The Trap of Gargantius | Stanislaw Lem | Constructor |
| Trurl(his lordship Trurl, Trurl the highborn, Trurl the illustrious constructor +8) — The Fourth Sally or How Trurl Built a Femfatalatron | The Fourth Sally or How Trurl Built a Femfatalatron | Stanislaw Lem | Constructor and protagonist |
| Trurl(Constructor) — The Second Sally or The Offer of King Krool | The Second Sally or The Offer of King Krool | Stanislaw Lem | Constructor |
| Trurl — The Seventh Sally or How Trurl's Own Perfection Led to No Good | The Seventh Sally or How Trurl's Own Perfection Led to No Good | Stanislaw Lem | protagonist |
| Trurl — The Sixth Sally or How Trurl and Klapaucius Created a Demon | The Sixth Sally or How Trurl and Klapaucius Created a Demon | Stanislaw Lem | Constructor and general omni-potentiary |
| Trurl(the furrin gentleman) — The Third Sally or The Dragons of Probability | The Third Sally or The Dragons of Probability | Stanislaw Lem | Constructor |
| Trurl — Trurl's Machine | Trurl's Machine | Stanislaw Lem | Protagonist / Constructor |
| Ts'ui Pen — The Form of the Sword | The Form of the Sword | Jorge Luis Borges | Ancestor, governor, writer |
| Ts'ui Pen — The Garden of Forking Paths | The Garden of Forking Paths | Jorge Luis Borges | Yu Tsun's great-grandfather |
| Ts'ui Pen — Tlön, Uqbar, Orbis Tertius | Tlön, Uqbar, Orbis Tertius | Jorge Luis Borges | Novelist/Ancestor |
| Tsh't(Tish-oot) — Startide Rising | Startide Rising | David Brin | Fourth officer, acting helmsman |
| Tsoldrin Beychae(Beychae) — Use of Weapons | Use of Weapons | Iain M. Banks | Scholar / Political figure |
| Tsuneo Sugiyama — Too Like the Lightning | Too Like the Lightning | Ada Palmer | Retired Journalist |
| Tulare — Timescape | Timescape | Gregory Benford | minor character |
| Tully Mardi — Perhaps the Stars | Perhaps the Stars | Ada Palmer | Architect of the limited war |
| Tully Mardi(Geneva, Tully Mojave, Tully +2) — Seven Surrenders | Seven Surrenders | Ada Palmer | Radical speaker and survivor |
| Tully Mardi(Tully, Tully Mardi Mojave) — The Will to Battle | The Will to Battle | Ada Palmer | Sniper's ally, oracle |
| Tuluy — The Approach to Al-Mu'tasim | The Approach to Al-Mu'tasim | Jorge Luis Borges | Military Leader |
| Turi — Network Effect | Network Effect | Martha Wells | other |
| Turner — Count Zero | Count Zero | William Gibson | Mercenary team leader / Protagonist |
| Turringen — The Foundation Trilogy | The Foundation Trilogy | Isaac Asimov | Calvinian robot / hard-liner |
| Twelve Azalea(Petal) — A Desolation Called Peace | A Desolation Called Peace | Arkady Martine | minor / deceased |
| Twelve Fusion — A Desolation Called Peace | A Desolation Called Peace | Arkady Martine | Ikantlos-prime to Sixteen Moonrise |
| Twenty Cicada(Swarm, ikantlos-prime, adjutant) — A Desolation Called Peace | A Desolation Called Peace | Arkady Martine | Ikantlos-prime, Nine Hibiscus's second-in-command |
| Twirl — The Circular Ruins | The Circular Ruins | Jorge Luis Borges | Congress delegate |
| Twirl — The Form of the Sword | The Form of the Sword | Jorge Luis Borges | Congress member |
| Two Cartograph(Map) — A Desolation Called Peace | A Desolation Called Peace | Arkady Martine | minor |
| Two Foam(Bubbles) — A Desolation Called Peace | A Desolation Called Peace | Arkady Martine | Comms officer, Weight for the Wheel |
| Two-a-Day — Count Zero | Count Zero | William Gibson | Software dealer / Fence |
| Tyador Borlú(Inspector Borlú, Boss, Tyador +5) — The City & The City | The City & The City | China Miéville | Inspector for the Besźel Extreme Crime Squad |
| Tycho — The Uplift War | The Uplift War | David Brin | Helper / animal |
| Tyler — Cyteen | Cyteen | C. J. Cherryh | Security operative |
| Tyler — Forever Peace | Forever Peace | Joe Haldeman | helper |
| Tyrathect(the Flenser Fragment, The Fragment, Mr. Skinner +2) — A Fire Upon the Deep | A Fire Upon the Deep | Vernor Vinge | actantial opponent / internal resistance |
| Tyrena Wingreen-Feif — Hyperion | Hyperion | Dan Simmons | Publisher/antagonist force |
| Tyy — Nova | Nova | Samuel R. Delany | Crewmate and Tarot reader |
| Tzinacan — The Circular Ruins | The Circular Ruins | Jorge Luis Borges | Priest / Prisoner |
| Tzinacan — Tlön, Uqbar, Orbis Tertius | Tlön, Uqbar, Orbis Tertius | Jorge Luis Borges | Priest/Prisoner |
| Uaithne(the Death Spirit) — Ammonite | Ammonite | Nicola Griffith | Echraidhe antagonist / Death Spirit claimant |
| Ubrel Shiol — Use of Weapons | Use of Weapons | Iain M. Banks | Jailer / Executioner |
| Uche — The Fifth Season | The Fifth Season | N.K. Jemisin | Essun's murdered son |
| Ulf Sigurdarson — The Circular Ruins | The Circular Ruins | Jorge Luis Borges | Icelander and skald |
| Uliet(Old Liet, Uliet the Old Liet) — Dune | Dune | Frank Herbert | Fremen executioner |
| Ulpiano Suárez(Suárez) — Tlön, Uqbar, Orbis Tertius | Tlön, Uqbar, Orbis Tertius | Jorge Luis Borges | Foreman |
| Ulver Seich(Ulver) — Excession | Excession | Iain M. Banks | Socialite / passenger |
| Umerue(Princess Umerue) — Paladin of Souls | Paladin of Souls | Lois McMaster Bujold | opponent |
| Umma Balsum — Perdido Street Station | Perdido Street Station | China Miéville | Communicatrix |
| Ummon(the megalith) — The Fall of Hyperion | The Fall of Hyperion | Dan Simmons | TechnoCore AI/Stable faction |
| Una — Blackout/All Clear | Blackout/All Clear | Connie Willis | Household staff |
| Uncle Enzo(Enzo) — Snow Crash | Snow Crash | Neal Stephenson | actantial:helper / actantial:subject |
| Uncle Tishlin(Tish) — Excession | Excession | Iain M. Banks | Holographic emissary |
| Unknown fairy (acorn-cup) — Among Others | Among Others | Jo Walton | helper |
| Unnamed Assailant(Beachcomber dude) — The Ministry for the Future | The Ministry for the Future | Kim Stanley Robinson | Eco-vigilante |
| Unnamed Human Man — Dawn | Dawn | Octavia E. Butler | Human survivor |
| unnamed man — A Closed and Common Orbit | A Closed and Common Orbit | Becky Chambers | minor/donor |
| unnamed new historian — Blackout/All Clear | Blackout/All Clear | Connie Willis | protagonist |
| Unnamed Slave Narrator — The Ministry for the Future | The Ministry for the Future | Kim Stanley Robinson | Freed captive |
| Unnamed Swiss critic(Swiss critic) — U-Write-It | U-Write-It | Stanislaw Lem | Cultural commentator |
| Unnamed Woman(She) — Stars in My Pocket Like Grains of Sand | Stars in My Pocket Like Grains of Sand | Samuel R. Delany | Rescuer / Kidnapper |
| Uphanad(Major Uphanad) — Ender's Game | Ender's Game | Orson Scott Card | MinCol head of security |
| Urmann — The Sect of the Phoenix | The Sect of the Phoenix | Jorge Luis Borges | Scholar (refuted) |
| Ursula — Blue Mars | Blue Mars | Kim Stanley Robinson | Scientist at Acheron |
| Ursula — Green Mars | Green Mars | Kim Stanley Robinson | First Hundred scientist |
| Ursula — Red Mars | Red Mars | Kim Stanley Robinson | First Hundred/Bogdanovist |
| Ursula K. Le Guin — The Left Hand of Darkness | The Left Hand of Darkness | Ursula K. Le Guin | extradiegetic narrator/author |
| Uth Shusgis(Commissioner Shusgis) — The Left Hand of Darkness | The Left Hand of Darkness | Ursula K. Le Guin | Orgota First Commensal District Commissioner |
| Uthacalthing — The Uplift War | The Uplift War | David Brin | Senior Tymbrimi diplomat, trickster, Athaclena's father |
| v'ea'd — Stars in My Pocket Like Grains of Sand | Stars in My Pocket Like Grains of Sand | Samuel R. Delany | Professor |
| Vala(Valavirgillin) — Ringworld | Ringworld | Larry Niven | helper |
| Valentine(Val, Demosthenes) — Speaker for the Dead | Speaker for the Dead | Orson Scott Card | Supporting character / sister |
| Valentine Michael Smith(Man from Mars, Mike, Smith +4) — Stranger in a Strange Land | Stranger in a Strange Land | Robert A. Heinlein | protagonist/messiah |
| Valerie(the vampire, prepost-Human, Valerie the Vampire) — Echopraxia | Echopraxia | Peter Watts | Vampire / Antagonist |
| Valerie Tommasino — Hell Is the Absence of God | Hell Is the Absence of God | Ted Chiang | Support group member |
| Van Ryberg(Pieter) — Childhood's End | Childhood's End | Arthur C. Clarke | Stormgren's assistant |
| van Tromp(Captain, Skipper) — Stranger in a Strange Land | Stranger in a Strange Land | Robert A. Heinlein | Exposition vehicle / returning hero |
| Vannevar Morgan(Dr. Smith, Chief Engineer, Van +1) — The Fountains of Paradise | The Fountains of Paradise | Arthur C. Clarke | Protagonist / Chief Engineer |
| Vara Liso — The Foundation Trilogy | The Foundation Trilogy | Isaac Asimov | Mentalic enforcer and antagonist |
| Vasa Luigi(Baron Bharaputra, the Baron) — Mirror Dance | Mirror Dance | Lois McMaster Bujold | opponent |
| Vassily Shitnovitzer — The Yiddish Policemen's Union | The Yiddish Policemen's Union | Michael Chabon | minor antagonist / witness |
| Vautrin — Rien du tout, ou la consequence | Rien du tout, ou la consequence | Stanislaw Lem | Fictional character |
| Vea — The Dispossessed | The Dispossessed | Ursula K. Le Guin | Urrasti socialite |
| Velvel — The Yiddish Policemen's Union | The Yiddish Policemen's Union | Michael Chabon | minor witness |
| Vendacious(Craddleheads) — A Fire Upon the Deep | A Fire Upon the Deep | Vernor Vinge | opponent / chamberlain |
| Vendetius Ultor of Amentia(the bass) — Tale of the Three Storytelling Machines of King Genius | Tale of the Three Storytelling Machines of King Genius | Stanislaw Lem | Professor and Avenger |
| Venerable Parakarma(Dr. Choam Goldberg, Swami Krisnamurthi) — The Fountains of Paradise | The Fountains of Paradise | Arthur C. Clarke | Opponent / Apostate scientist-monk |
| Verger — To Say Nothing of the Dog | To Say Nothing of the Dog | Connie Willis | Minor |
| Verity(Miss Brown, Kindle, Cousin +2) — To Say Nothing of the Dog | To Say Nothing of the Dog | Connie Willis | Fellow historian operative |
| Verity Jane(Verity, app whisperer) — Agency | Agency | William Gibson | App whisperer, primary human contact for Eunice |
| Vermishank — Perdido Street Station | Perdido Street Station | China Miéville | Head of University Science Faculty / Project Administrator |
| Vianca — Spook Country | Spook Country | William Gibson | Associate of Tito |
| Vic — Snow Crash | Snow Crash | Neal Stephenson | helper |
| Victor(Victor Colon) — Fledgling | Fledgling | Octavia E. Butler | Captive mercenary |
| Victor Dominic — Dawn | Dawn | Octavia E. Butler | Human survivor |
| Victor Dominic(Vidor Domonkos) — Imago | Imago | Octavia E. Butler | Human survivor |
| Victor Whatmough(Vic) — Stand on Zanzibar | Stand on Zanzibar | John Brunner | vignette |
| Victoria — Stand on Zanzibar | Stand on Zanzibar | John Brunner | minor |
| Vidal Vordarian(Count Vordarian, Commodore Count Vordarian, Commodore Vordarian +2) — Barrayar | Barrayar | Lois McMaster Bujold | actantial opponent |
| Vijjika — Green Mars | Green Mars | Kim Stanley Robinson | supporting |
| Vijjika — Red Mars | Red Mars | Kim Stanley Robinson | Sanctuary host / Bogdanovist |
| Viktor Runeberg(Hans Rabener) — The Form of the Sword | The Form of the Sword | Jorge Luis Borges | Prussian spy |
| Viktor Runeberg(Hans Rabener) — The Garden of Forking Paths | The Garden of Forking Paths | Jorge Luis Borges | Prussian spy |
| Vincent Moon(John Vincent Moon, the Englishman at La Colorada, The scarred narrator +1) — The Form of the Sword | The Form of the Sword | Jorge Luis Borges | Traitor/Landowner |
| Vincent Moon(Narrator) — Tlön, Uqbar, Orbis Tertius | Tlön, Uqbar, Orbis Tertius | Jorge Luis Borges | Traitor/Narrator |
| Vincent Silver(Dr. Silver) — I, Robot | I, Robot | Isaac Asimov | Director of Research, U.S. Robots (successor period) |
| Vincenzo Giuliani(Father General, Giuliani, Vince +1) — The Sparrow | The Sparrow | Mary Doria Russell | Jesuit Father General conducting the post-mission inquiry |
| Vincio — Ammonite | Ammonite | Nicola Griffith | Danner's personal assistant |
| Vindarten — Childhood's End | Childhood's End | Arthur C. Clarke | Overlord companion |
| Vine — Ammonite | Ammonite | Nicola Griffith | Sailor; Thenike's long-term partner |
| Vinessa — Anxiety Is the Dizziness of Freedom | Anxiety Is the Dizziness of Freedom | Ted Chiang | Dana's Former Best Friend |
| Virgil — Agency | Agency | William Gibson | Protective crew member |
| Virlomi — Ender's Game | Ender's Game | Orson Scott Card | Indian resistance leader |
| Vitaly Chernobyl — Snow Crash | Snow Crash | Neal Stephenson | minor |
| Viv — Blackout/All Clear | Blackout/All Clear | Connie Willis | Shelter regular |
| Vivien Ancelet(President Ancelet) — Perhaps the Stars | Perhaps the Stars | Ada Palmer | President of the Humanists |
| Vivien Ancelet(Censor, The Anonymous, Seventh Anonymous) — Seven Surrenders | Seven Surrenders | Ada Palmer | Censor / The Anonymous |
| Vivien Ancelet(President of the Humanist Hive, Anonymous, President Ancelet +1) — The Will to Battle | The Will to Battle | Ada Palmer | President of the Humanists |
| Vivien Ancelet(The Censor, Vivien, Ancelet) — Too Like the Lightning | Too Like the Lightning | Ada Palmer | Romanovan Censor |
| Vlad — Blue Mars | Blue Mars | Kim Stanley Robinson | First Hundred / strategist |
| Vlad — Green Mars | Green Mars | Kim Stanley Robinson | First Hundred scientist / eco-economics theorist |
| Vlad — Red Mars | Red Mars | Kim Stanley Robinson | First Hundred scientist / strategist |
| Vlade — New York 2140 | New York 2140 | Kim Stanley Robinson | Superintendent of the Met Life tower |
| Vladimir Leontyev(Konstantin, Vladimir, Vlad) — Fledgling | Fledgling | Octavia E. Butler | Shori's elderfather and advocate |
| Voiceover — Liking What You See: A Documentary | Liking What You See: A Documentary | Ted Chiang | Narrator for PEN commercial |
| Volescu — Ender's Game | Ender's Game | Orson Scott Card | Antagonist / compromised geneticist |
| Voltaire — The Foundation Trilogy | The Foundation Trilogy | Isaac Asimov | trickster/interior presence |
| Voltaire — The Will to Battle | The Will to Battle | Ada Palmer | Utopian spokesperson |
| Voltaire Seldon(Patriarch) — Too Like the Lightning | Too Like the Lightning | Ada Palmer | Nowhere child |
| Vondramach Okk(Vondramach, Vondramach Tyrannus, Dramach +1) — Stars in My Pocket Like Grains of Sand | Stars in My Pocket Like Grains of Sand | Samuel R. Delany | Historical Figure/Poet |
| Vortala(Prime Minister Vortala) — Barrayar | Barrayar | Lois McMaster Bujold | actantial helper |
| Voytek(Blond boy) — Pattern Recognition | Pattern Recognition | William Gibson | Artist and acquaintance |
| Wahram — 2312 | 2312 | Kim Stanley Robinson | Diplomat / Colleague |
| Wainwright(Alexander Wainwright) — Childhood's End | Childhood's End | Arthur C. Clarke | Head of the Freedom League |
| Waiter(Bellman in Brussels) — Count Zero | Count Zero | William Gibson | Undercover operative |
| Walter Gripp(Gripp) — The Martian Chronicles | The Martian Chronicles | Ray Bradbury | protagonist |
| Walter James(Walter) — Queen of the States | Queen of the States | Lisa Goldstein | Helper / potential suitor |
| Walter Lambert — Liking What You See: A Documentary | Liking What You See: A Documentary | Ted Chiang | President of the National Calliagnosia Association |
| Walter Lambert — Stories of Your Life and Others | Stories of Your Life and Others | Ted Chiang | President of the National Calliagnosia Association |
| Wang Wei(Wang) — 2312 | 2312 | Kim Stanley Robinson | Principal Investigator |
| Wang Zhanmin(Wang, Wang the Man) — Pushing Ice | Pushing Ice | Alastair Reynolds | Commander of Shenzhou Five |
| Warbaby — Virtual Light | Virtual Light | William Gibson | Corporate operative |
| Warden Patterson(G. Patterson) — American Gods | American Gods | Neil Gaiman | minor |
| Warder(Peggy) — To Say Nothing of the Dog | To Say Nothing of the Dog | Connie Willis | Oxford console operator |
| Warren Davidson — Liking What You See: A Documentary | Liking What You See: A Documentary | Ted Chiang | 1st-year student |
| Warren Kingsley — The Fountains of Paradise | The Fountains of Paradise | Arthur C. Clarke | Helper / Structural engineer |
| Wasco — The Years of Rice and Salt | The Years of Rice and Salt | Kim Stanley Robinson | Envoy from Hodenosaunee League |
| Waters(Wat, Bill) — Lost Futures | Lost Futures | Lisa Tuttle | deceased brother |
| Wattaceti — Startide Rising | Startide Rising | David Brin | Neo-dolphin communications/detection officer |
| Weal — Ammonite | Ammonite | Nicola Griffith | Headwoman of olla shapers band |
| Webber — Count Zero | Count Zero | William Gibson | Mercenary |
| Wednesday(Mr. Wednesday, James O'Gorman, Jimmy +7) — American Gods | American Gods | Neil Gaiman | Employer / trickster antagonist |
| Wellington Ma — Virtual Light | Virtual Light | William Gibson | Lawyer |
| Wendy — Exhalation | Exhalation | Ted Chiang | Derek's wife |
| Wendy — The Lifecycle of Software Objects | The Lifecycle of Software Objects | Ted Chiang | Derek's wife |
| Wendy Mae(Wednesday, Wench, Window) — Les Robinsonades | Les Robinsonades | Stanislaw Lem | Imaginary Love Interest |
| Wenn — Ammonite | Ammonite | Nicola Griffith | helper |
| Wenyk(QM) — Take Back Plenty | Take Back Plenty | Colin Greenland | secondary |
| Wernher von Braun — The Calculating Stars | The Calculating Stars | Mary Robinette Kowal | minor |
| Wes — Cyteen | Cyteen | C. J. Cherryh | Security medic |
| West(Lieutenant West, Chief Engineer West) — Redshirts | Redshirts | John Scalzi | Bridge officer |
| West(Ellery West) — The Demolished Man | The Demolished Man | Alfred Bester | Minor helper |
| Whiskey Jack(Wisakedjak) — American Gods | American Gods | Neil Gaiman | helper (resistant) |
| Whistle — Die Kultur als Fehler | Die Kultur als Fehler | Stanislaw Lem | Anthropologist |
| Whitby(Dead Whitby, Real Whitby, False Whitby) — Acceptance | Acceptance | Jeff VanderMeer | Southern Reach Scientist |
| Whitby — Authority | Authority | Jeff VanderMeer | Southern Reach Scientist |
| Wiktor Marchwinska-Wyrwal(Wiktor) — Pattern Recognition | Pattern Recognition | William Gibson | Polish security chief |
| Wilf Netherton(Netherton, Wilf) — Agency | Agency | William Gibson | Operative and cross-timeline communicator |
| Wilf Netherton(Netherton, Wilf, Associate Curator Annie Courrèges +1) — The Peripheral | The Peripheral | William Gibson | Publicist, Flynne's guide |
| Wilhelm Klopper(Privatdozent W. Klopper, Klopper) — A Perfect Vacuum | A Perfect Vacuum | Stanislaw Lem | Fictional Author |
| Wilhelm Klopper(Privatdozent W. Klopper, Herr Dozent Klopper) — Die Kultur als Fehler | Die Kultur als Fehler | Stanislaw Lem | Fictional Author |
| Wilhelmina McCullough(Mina) — Omphalos | Omphalos | Ted Chiang | Daughter of Dr. McCullough, relic thief |
| Wilkie Collins — The Approach to Al-Mu'tasim | The Approach to Al-Mu'tasim | Jorge Luis Borges | Author |
| William Fort(Fort) — Red Mars | Red Mars | Kim Stanley Robinson | Praxis founder, Terran visitor |
| William James — Rien du tout, ou la consequence | Rien du tout, ou la consequence | Stanislaw Lem | Philosopher |
| William Mandella(Lieutenant Mandella, 2LT Mandella, Old Queer +3) — The Forever War | The Forever War | Joe Haldeman | protagonist-narrator |
| William Ryder(Sir Geoffrey, Geoffrey, Will) — Queen of the States | Queen of the States | Lisa Goldstein | Helper / grieving patron |
| Williamson — The Martian Chronicles | The Martian Chronicles | Ray Bradbury | Crew member |
| Willie Dick — The Yiddish Policemen's Union | The Yiddish Policemen's Union | Michael Chabon | Helper / Tlingit law enforcement |
| Willy Jude(Blind Willy Jude) — Idoru | Idoru | William Gibson | Lo/Rez Drummer |
| Wilson — American Gods | American Gods | Neil Gaiman | minor |
| Wim — Among Others | Among Others | Jo Walton | romantic interest / karass member |
| Win — Pattern Recognition | Pattern Recognition | William Gibson | Cayce's father |
| Winston Blount(Winnie, Dean Blount) — Rainbows End | Rainbows End | Vernor Vinge | actantial:sender |
| Winston Churchill(Duke of London, Mr Churchill, the Prime Minister +1) — The Separation | The Separation | Christopher Priest | Historical figure / antagonist to peace |
| Winston Smith(6079 Smith W.) — 1984 | 1984 | George Orwell | protagonist |
| Wisdom Like Silence — Excession | Excession | Iain M. Banks | Ship Mind |
| Witch doctors — Tlön, Uqbar, Orbis Tertius | Tlön, Uqbar, Orbis Tertius | Jorge Luis Borges | Rulers/Seers |
| Wolfgang(Wolfgang Korsakov, Wolf) — The Moon Is a Harsh Mistress | The Moon Is a Harsh Mistress | Robert A. Heinlein | Revolutionary council member/financier |
| Wolinsky(Frida) — Pushing Ice | Pushing Ice | Alastair Reynolds | EVA Worker |
| Woman from parktown — Use of Weapons | Use of Weapons | Iain M. Banks | Visitor / Prostitute |
| Woodcarver(the Queen) — A Fire Upon the Deep | A Fire Upon the Deep | Vernor Vinge | actantial helper / ruler |
| Wounded Companion — The Dispossessed | The Dispossessed | Ursula K. Le Guin | Protester |
| Wray Ordway(Wray) — Adulthood Rites | Adulthood Rites | Octavia E. Butler | Guest house keeper |
| Wray Ordway(Wray) — Imago | Imago | Octavia E. Butler | Human male in village |
| Wright(my first) — Fledgling | Fledgling | Octavia E. Butler | Shori's symbiont and companion |
| Wright(Minister, Gospodin Wright) — The Moon Is a Harsh Mistress | The Moon Is a Harsh Mistress | Robert A. Heinlein | actantial:opponent |
| Writer for the Yiddische Zeitung — Death and the Compass | Death and the Compass | Jorge Luis Borges | Journalist |
| Wyoming Knott(Wyoh, Wye, Betty +2) — The Moon Is a Harsh Mistress | The Moon Is a Harsh Mistress | Robert A. Heinlein | Revolutionary organizer from Hong Kong Luna |
| Xappish lieutenants (elder and junior) — Startide Rising | Startide Rising | David Brin | Minor Galactic POV characters |
| Xiaoliu Accursed-Through-the-Ages-Guildbreaker(Xiaoliu) — Perhaps the Stars | Perhaps the Stars | Ada Palmer | Masonic Official |
| Xiaoliu Guildbreaker(Archptraitor, Familiaris) — Perhaps the Stars | Perhaps the Stars | Ada Palmer | Traitorous Official |
| Xiaoliu Guildbreaker(Grandma, Mason Guildbreaker Senior, Unofficial Nonpartisan Resolver of Unnecessary Bickering +2) — The Will to Battle | The Will to Battle | Ada Palmer | Spouse of Martin Guildbreaker |
| Xinwu — The Years of Rice and Salt | The Years of Rice and Salt | Kim Stanley Robinson | Member of Kang's household |
| Xiu Xiang(Newbie Xiang, Dr. Xiang, Xiu +2) — Rainbows End | Rainbows End | Vernor Vinge | supporting |
| Xtasca(the Cherub, it, she) — Take Back Plenty | Take Back Plenty | Colin Greenland | Cherub, fifth member of Contraband |
| Xuánlóng(Doctor Horizon Sanjeevani) — Perhaps the Stars | Perhaps the Stars | Ada Palmer | Medical officer / Delian Skyshepherd |
| Xul Solar — Ficciones (Tlön, Uqbar, Orbis Tertius) | Ficciones (Tlön, Uqbar, Orbis Tertius) | Jorge Luis Borges | Translator |
| Y.T.(Yours Truly, Whitey (misconstrued)) — Snow Crash | Snow Crash | Neal Stephenson | actantial:helper |
| Y.T.'s Mom — Snow Crash | Snow Crash | Neal Stephenson | other |
| Yagharek(Too Too Abstract Individual Yagharek Not To Be Respected, Yag, bird-man) — Perdido Street Station | Perdido Street Station | China Miéville | Garuda companion |
| Yakub(The Masked One) — Tlön, Uqbar, Orbis Tertius | Tlön, Uqbar, Orbis Tertius | Jorge Luis Borges | Condemned man |
| Yama(deathgod, Yama-Dharma, Lord of Death +4) — Lord of Light | Lord of Light | Roger Zelazny | antagonist / complex figure |
| Yamazaki(Scooter) — Virtual Light | Virtual Light | William Gibson | Researcher/Sociologist |
| Yan Kansarv — The Foundation Trilogy | The Foundation Trilogy | Isaac Asimov | ancient robot / diagnostician |
| Yanni Schwartz(Yanni, YS) — Cyteen | Cyteen | C. J. Cherryh | Senior Reseune researcher and administrator |
| Yanu — American Gods | American Gods | Neil Gaiman | secondary character |
| Yasmina — The Years of Rice and Salt | The Years of Rice and Salt | Kim Stanley Robinson | other |
| Yates — The Windup Girl | The Windup Girl | Paolo Bacigalupi | Former factory operator (deceased/departed) |
| Yawning Angel — Excession | Excession | Iain M. Banks | GSV |
| Yegey(Commensal Yegey) — The Left Hand of Darkness | The Left Hand of Darkness | Ursula K. Le Guin | Commensal host / Open Trade faction |
| Yeli Zudov(Yeli) — Blue Mars | Blue Mars | Kim Stanley Robinson | actantial:helper |
| Yeli Zudov(Yeli) — Red Mars | Red Mars | Kim Stanley Robinson | helper |
| Yevi Hart(Yevi) — Cyteen | Cyteen | C. J. Cherryh | other |
| Ykka(Yeek) — The Fifth Season | The Fifth Season | N.K. Jemisin | Leader of Castrima |
| Ykka — The Stone Sky | The Stone Sky | N. K. Jemisin | Comm leader / helper |
| Ylastimil Kouska — De Impossibilitate Vitae / De Impossibilitate Prognoscendi | De Impossibilitate Vitae / De Impossibilitate Prognoscendi | Stanislaw Lem | Ancestor |
| Ylla(Mrs. K) — The Martian Chronicles | The Martian Chronicles | Ray Bradbury | Protagonist (Ylla) |
| Ynn — Stars in My Pocket Like Grains of Sand | Stars in My Pocket Like Grains of Sand | Samuel R. Delany | Medical/Investigative Official |
| Yolanda Rodriguez(Yolanda) — The City & The City | The City & The City | China Miéville | Archaeology student and friend of Mahalia |
| Yorgos Setsumi(Yorgy) — Nova | Nova | Samuel R. Delany | Lorq's old friend |
| Yori — Adulthood Rites | Adulthood Rites | Octavia E. Butler | Former psychiatrist and resister |
| Yori — Imago | Imago | Octavia E. Butler | Human psychiatrist and resister |
| Yorj Syedr(Major Yorj Syedr, Councillor) — The City & The City | The City & The City | China Miéville | Besź politician, leader of National Bloc |
| Yorjavic(killer, shooter, murderer) — The City & The City | The City & The City | China Miéville | Sniper and assassin |
| Young Emperor Chia-Ch'ing — Tlön, Uqbar, Orbis Tertius | Tlön, Uqbar, Orbis Tertius | Jorge Luis Borges | Emperor |
| Young man(the youth, the boy) — Use of Weapons | Use of Weapons | Iain M. Banks | Murderer / Attacker |
| Young man from Northrising(the new member) — The Dispossessed | The Dispossessed | Ursula K. Le Guin | Aggressive PDC member |
| young thug(the young thug with the Indian-looking face) — The South | The South | Jorge Luis Borges | antagonist |
| Younger Jorge Luis Borges(Alter ego, Narrator) — The Circular Ruins | The Circular Ruins | Jorge Luis Borges | Alter ego |
| Yskandr Aghavn — A Desolation Called Peace | A Desolation Called Peace | Arkady Martine | Mahit's imago-predecessor; internal voice |
| Yueh(Wellington, Doctor Yueh, el buen doctor) — Dune | Dune | Frank Herbert | actantial:opponent (latent traitor) |
| Yuuji Sajaki(Sajaki, Komuso) — Revelation Space | Revelation Space | Alastair Reynolds | Triumvir and ship leader |
| Zadkiel F. Obomi(Zad, Old Zad) — Stand on Zanzibar | Stand on Zanzibar | John Brunner | head of state |
| Zafir — Blue Mars | Blue Mars | Kim Stanley Robinson | Helper / technical expert |
| Zafir — Red Mars | Red Mars | Kim Stanley Robinson | helper |
| Zahhar — The Years of Rice and Salt | The Years of Rice and Salt | Kim Stanley Robinson | Senior madressa mathematician |
| Zaneeta — The Years of Rice and Salt | The Years of Rice and Salt | Kim Stanley Robinson | Supporting |
| Zareenah — Anxiety Is the Dizziness of Freedom | Anxiety Is the Dizziness of Freedom | Ted Chiang | Support Group Member |
| Zasha(Z) — 2312 | 2312 | Kim Stanley Robinson | Earth Resident / Pharm Operator |
| Zeya — The Years of Rice and Salt | The Years of Rice and Salt | Kim Stanley Robinson | Supporting |
| Zeyk — Blue Mars | Blue Mars | Kim Stanley Robinson | Arab elder, eyewitness to Boone's murder |
| Zeyk — Green Mars | Green Mars | Kim Stanley Robinson | Arab Martian elder; underground participant |
| Zeyk — Red Mars | Red Mars | Kim Stanley Robinson | Arab community elder at Nicosia |
| Zeyk — The Years of Rice and Salt | The Years of Rice and Salt | Kim Stanley Robinson | opponent |
| Zheng He — The Years of Rice and Salt | The Years of Rice and Salt | Kim Stanley Robinson | supporting |
| Zhu Isao(Zhu Tuanjie-kexue) — The Years of Rice and Salt | The Years of Rice and Salt | Kim Stanley Robinson | revolutionary philosopher/historian |
| Zhu Weichun — Too Like the Lightning | Too Like the Lightning | Ada Palmer | Traitorous security captain |
| Zim(platoon sergeant, Brevet Captain Zim, Sarge) — Starship Troopers | Starship Troopers | Robert A. Heinlein | helper/mentor |
| Zipperupus(King of the Partheginians, the Deutons, and the Profligoths) — Tale of the Three Storytelling Machines of King Genius | Tale of the Three Storytelling Machines of King Genius | Stanislaw Lem | Monarch |
| Zipperupus(King Zipperupus) — The Cyberiad | The Cyberiad | Stanislaw Lem | King of the Partheginians, Deutons, and Profligoths |
| Zombie Guard — Echopraxia | Echopraxia | Peter Watts | Guard |
| Zona Rosa(Mercedes Purissima Vargas-Gutierrez) — Idoru | Idoru | William Gibson | Lo/Rez Fan / Hacker |
| Zorma — The Foundation Trilogy | The Foundation Trilogy | Isaac Asimov | Calvinian robot / mediator |
| Zorya Polunochnaya — American Gods | American Gods | Neil Gaiman | Donor / threshold figure |
| Zorya Utrennyaya — American Gods | American Gods | Neil Gaiman | Minor helper |
| Zorya Vechernyaya — American Gods | American Gods | Neil Gaiman | Minor helper |
| Zreyn Tramow(Honorary Contact Fleet Captain Gart-Kepilesa Zreyn Enhoff Tramow Afayaf dam Niskat-west) — Excession | Excession | Iain M. Banks | Ship Captain |
| Zulfikar Sharif(Mr. Rabbit, Mysterious Stranger, Rabbit +4) — Rainbows End | Rainbows End | Vernor Vinge | trickster |
| Zunli — The Years of Rice and Salt | The Years of Rice and Salt | Kim Stanley Robinson | Member of Kang's household |