- Counterstrike: The Last World War, Book 2
- Coup d'Envoi
- Coup d'Etat
- Coup D’état
- Court-Martial on the Charys
- Courting Trouble
- Cousin Entropy
- Coven; Short Stories of Sci-fi and Fantasy
- Covenant
- Coventina
- Cover
- Covert Defense Force: Sake of Time
- COVERT MESSAGES
- Coverup
- Covfefe Syndrome
- Cow Fart Apocalypse
- Cowboy Angels
- Cowboy Knight Salvation
- Cowboy Samurai X Badass Android
- Cowboys and Indians
- Cowl
- Cows!
- Coyote
- Coyote Ugly
- Crache
- Crack of Doom
- Cracking the Sky
- Cracks in the Pillars
- Cradle and Grave
- Cradle of Fire
- Cradle of the Sun
- Craft Book
- Crankie Williams Does Penance
- Crankie Williams Goes Ballistic
- Crankie Williams Goes Pirate
- Crankie Williams Goes to War
- Crash
- Crash Landing
- Crash Wagon: Book One - Family Ties
- Crash Wagon: Book Three - Enemies and Allies
- Crash Wagon: Book Two - Menomonee Falls
- Crash, Part 3 of Ashor's Tale
- Crashed in the Outlands ~ Sci-Fi Alien Erotic Adventure
- Crashed: Science Fiction Romance
- Crashtown
- Crated Glory
- Crater Trueblood and the Lunar Rescue Company
- Craving Space
- Crawlspace
- Crazy Days
- Crazy Rich Aliens
- Crazy Stories: Volume 2 - To Reap or to Sow
- Creating The Myth: A Prequel To "Stranger Than Fiction", Book 1: The Promise Of Redemption
- Creation & Why
- Creation Machine
- Creations
- Creations: The Calling Series (Book 3)
- Creativitate artificială (Proză științifico-fantastică)
- Creator's End
- Creators
- Creators of the Galaxy
- Creatura
- Creature from Cleveland Depths
- Creature Hunt on Planet Toaria
- Creatures
- Creatures of the Light
- Creatures of the Night
- Creed of the Stars:
- Creep
- Creepier by the Dozen: Twelve Twisted Tales
- Creepies: Twisted Tales From Beneath the Bed
- Cren Siblis: Slave Planet
- Crescent
- Crescent Earth
- Crestahn Kingdom
- Cretaceous Dawn
- Crew Extraction
- Crewel Lye
- Cries from the Dust
- Crilen and the War of False Prophets
- Crimean Fairy Tale
- Crimes Against Humanity
- Crimes Against Time
- Crimes of the Hub
- Criminal Justice
- Criminals Within
- Crimson
- Crimson Fire
- Crimson Son
- Crimson Son 2: Motherland
- Crimson Son 3: Ashes
- Crimson Son 4: Legacy
- Crimson Star
- Crimson Tattoo, Midnight Chronicles Book Three
- Crimson Tempest
- Crionizados
- Crises and Conflicts
- Crisis at Validor
- Crisis Averted
- Crisis Evolution
- Crisis in the Ashes
- Crisis of Consciousness
- Crisis on Callisto
- Crisis On Flight 101
- Crisis On Sandar
- Critical Contingencies
- Critical Point
- Crocalypse
- Crompton Divided
- Cronaca galattica
- Cronache da New Heaven
- Cronache dalla seconda guerra dell’acqua
- Cronache dell'Armageddon
- Cronache di Tuhitun. Selzerorg
- Cronache di Wolfopolis I
- Crone’s Revenge, Femspec Issue 6.2
- Cronotopo
- Cronus
- Crooked Pieces: Future Grit And Hard-Boiled Action - Part One
- Crooked Pieces: Future Grit And Hard-Boiled Action - Part Three
- Crooked Pieces: Future Grit And Hardboiled Action - Part Two
- Crooked Stars
- Crooked V.1
- Cross Council
- Cross Evolution
- Cross, the Hunter
- Cross-Stitch
- Crossbreed
- Crosscurrent: Star Wars
- Crossed Circuits: Sci-Fi Short Stories - Volume 1
- Crossed Circuits: Sci-Fi Short Stories - Volume II
- Crossed Circuits: Sci-Fi Short Stories - Volume III
- Crossed Circuits: Sci-Fi Short Stories - Volume IV
- Crossed Wires
- Crosses and Runes
- Crossfire
- Crossfire & Other Stories
- Crossing Point