- Clockwork Victoria
- Clockwork Villains
- Clockworks and Corsets
- Clone Rebellion 1: Republik
- Clone Rebellion 2: Abtrünnig
- Clone Rebellion 3: Allianz
- Clone Wars: Wild Space
- Cloné
- Close Encounters
- Close Encounters of the Alien Kind
- Close Encounters With the Deity
- Close Enough
- Close to Critical
- Closed Hearts
- Closer Than Touch
- Closer to the Edge
- Closing Down
- Cloud Atlas
- Cloud Cuckoo Land
- Cloudrock
- Clouds and Darkness
- Clouds Before Rain
- Clouds of Crom
- Clouds of Darkness
- Clowns Vs Zombies
- Club 5 Eight Zero 6
- CNSEV Tormalinas, Lost
- Co-Or
- Coalescent
- Coalition Reckoning
- Coastal Event Memories Volume I
- Coby's Treasure
- Cockiest Red Planet Trilogy Box Set
- Cocoon
- Code 2-18: Intermission One - Black Breeze (Racconto Technothriller)
- Code 2-18: Intermission Two - FOG of War
- Code 2-18: Surreal - Step Three
- Code 2-18: Surreal - Step Two
- Code 47 to BREV Force QuizMaster MixMatcher
- Code EMP
- Code Name
- Code Name Atlas
- Code of the Kyoushi
- Code Red
- Codename: Velocity
- Codgerspace
- Codice Redox - La sesta compagnia
- Coexistence
- Cofanetto La Colonia
- Cofanetto Programma Spose Interstellari
- Coffee Cup Dreams (A Redpoint One Romance)
- Coffee? Perhaps Tea?
- Cog
- Cogs and Corsets: The Anise Buttersby Series Book 1
- Cogs: Grease, Dust, Steam, & Magyk (An Aeropæia Story)
- Coiled Danger
- Coiled Vengeance
- Cold As Ice
- Cold Comfort & Other Tales
- Cold Energy. The Alex Cave Series Book 2
- Cold Fusion (The Apocalypse Series, Book 2)
- Cold Hands, Warm Heart
- Cold Magic
- Cold Nightmares
- Cold Reboot
- Cold Revenge
- Cold Reboot
- Cold Revenge
- Cold Snap
- Cold Storage
- Cold Victory
- Cold War
- Cold Welcome
- Cold Zero
- COLECCIÓN DEL PROGRAMA DE NOVIAS INTERESTELARES
- Colección del Programa de Novias Interestelares
- Colei che ferma il tempo
- Colerianischer Herbst
- Collaborators
- Collapse
- Collapse and Delusion
- Collar
- Collateral Damage
- Collected Essays
- Collected Novels, Short Stories, Essays and Articles
- Collected Science Fiction Short Stories: Volume Five
- Collected Science Fiction Short Stories: Volume Four
- Collected Science Fiction Short Stories: Volume One
- Collected Science Fiction Short Stories: Volume Six
- Collected Science Fiction Short Stories: Volume Three
- Collected Science Fiction Short Stories: Volume Two
- Collected: A Cybil Lewis SF Mystery Collection
- Collecting Stars
- Collector Ship
- Collezione privata
- Colliding Worlds Vol. 1: A Science Fiction Short Story Series
- Collision
- Collision with Chronos