- C-Vac
- C. C. Blake's Sweaty Space Operas, Issue 10
- C. C. Blake's Sweaty Space Operas, Issue 11
- C. C. Blake's Sweaty Space Operas, Issue 3
- C. C. Blake's Sweaty Space Operas, Issue 5
- C. C. Blake's Sweaty Space Operas, Issue 6
- C. C. Blake's Sweaty Space Operas, Issue 7
- C. C. Blake's Sweaty Space Operas, Issue 8
- C. C. Blake's Sweaty Space Operas, Issue 9
- C. S. Lewis Bible
- C. S. Lewis Essay Collection
- C.A.I.T.: Cyber Automated Intergrated Technology
- C.A.T.
- C.A.T.S.P.A.W. Computer Augmented Timeing System Particle Acceleration Weapon
- C.L.O.W.N. 242
- Cabal of Lies
- Caballero Alienígena: Problemas con el oso de felpa
- Caccia all'uomo
- Caccia alla fenice (Urania)
- Caccia allo Snark
- Cade Chandra 1: Jäger der Erinnerungen
- Cade Chandra 2: Jäger des Mondsilbers
- Cade Chandra 3: Jäger der goldenen Götter
- Cade Chandra 4: Jäger der Lebensformel
- Cade Chandra 5: Jäger des Mysteriums
- Cade Chandra 6: Jäger der Apokalypse
- Cadeau - Volume I - Who Can You Trust?
- Cadre
- Cael Civilization
- Caelestis Series: Books 1-3 Plus Aelwyd
- Caesar's Bicycle
- Caesar's Jaguar, Chariot Of The God's
- Caine Black Knife
- Caine's Law
- Caine's Mutiny
- Cakewalk to Gloryanna
- Calamity
- Calamity's Child
- Calculated Risk
- Calde of the Long Sun
- Caldera 12: Kingdom Come
- Calea speranței
- CalHouse I: Leonis Manor
- CalHouse II: Fort Sacramento
- CalHouse III: The Island
- Caliban
- Caliban's World
- Calibans Krieg
- Calico Kids
- Califia's Daughters
- Call Me Meola
- Call Me Pharaoh
- Call Me Wizard
- Call My Name
- Call of Destiny
- Call of Destiny (One Small Step out of the Garden of Eden,#1)
- Call of Home
- Call of the Savage
- Call of the Syron
- Call of the Void
- Call to Arms (Star Crusades Nexus, Book 6)
- Calliope
- Calliope 7
- Calliope and the Engine Smith
- Calliope and the Sea Serpent
- Callisto Megabundle: The Complete Series (Science Fiction Romance)
- Camelot 2050
- Camelot Crypto 1- Crypto Genesis
- Camelot Crypto 2- Crypto Odyssey
- Camelot Crypto 3- Crypto Symbiosis
- Camelot Crypto: Three Short Crypto-currency Stories
- Caminante sin recuerdos
- Camouflage
- Camp Despair
- Camp Nameless
- Campfire Chronicles
- Camping on Other Planets
- Campo di maggio
- Can't Shoot Straight Gang
- Canal Days
- Cancer World
- Canis Borg: Alien Control Agent
- Canopy of Hope
- Canto Bight (Star Wars)
- Capacity
- Capella's Golden Eyes
- Capitan Low
- CAPITAN SIN NOMBRE
- Capoeira: A Tale of Martial Arts Mastery, Mysticism and Love
- Capsule
- Captain
- Captain Commander
- Captain Disco: A New Disco
- Captain Flandry: Defender of the Terran Empire
- Captain Future #10: Outlaws of the Moon
- Captain Future #12: The Comet Kings
- Captain Future #13: Planets in Peril
- Captain Future #15: Worlds to Come
- Captain Future #16: The Star of Dread
- Captain Future #17: Magic Moon
- Captain Future #18: Days of Creation
- Captain Future #1: The Space Emperor
- Captain Future #22: The Return of Captain Future
- Captain Future #25: Pardon My Iron Nerves
- Captain Future #26: Moon of the Unforgotten
- Captain Future #28: Birthplace of Creation
- Captain Future #2: Calling Captain Future
- Captain Future #3: Captain Future's Challenge
- Captain Future #6: Star Trail to Glory
- Captain Future #7: The Magician of Mars
- Captain Future #8: The Lost World of Time
- Captain Future #9: Quest Beyond the Stars
- Captain Future: 1,500 Light Years from Home
- Captain Future: The Guns of Pluto
- Captain Goodheart - Against The Power of R.I.M.
- Captain Justo from the Planet Is
- Captain Justo Saga, Captain Justo From the Planet Is Log 1.1: Gold From the Sky
- Captain Justo Saga, Captain Justo From the Planet Is Log 1.2: Dangerous Training
- Captain Justo Saga, Captain Justo From the Planet Is Log 1.3: Homeland Attack
- Captain Justo Saga, Valley of Bones Log 2.1: Into the Deep
- Captain Justo Saga, Valley of Bones Log 2.2: The Seratian Betrayal
- Captain Justo Saga, Valley of Bones Log 2.3: Valley of Bones
- Captain Justo, Valley of Bones
- Captain Mike
- Captain of the Kali
- Captain Virtue and The League of Evil
- Captain's Boy
- Captain's Call Book Four
- Captain's Call Book One
- Captain's Call Book Three
- Captain's Call Book Two
- Captain's Final Log Entry
- Captain's Memories
- Captive and Consequences
- Captive Scorpio [Dray Prescot #17]
- Captives
- Captives in Obscurity
- Captives of the Song
- Captives of the Thieve-Star
- Captivity
- Capture: The Relissarium Wars Space Opera Series, Book 6
- Captured by the Cyborg - Alien Romance
- Carakenne - A Journey to Nyorfias Novella
- Caravan
- Caravana
- Caravane
- Carbon Heart Silicon Soul: Books 1 - 3 (Jupiter, Juno, and Juventas)
- Carbon Heart Silicon Soul: Books 4 - 5
- Carboxy
- Carcassonne