- Citadel (Cardassia)
- Citadel Var'Theldun
- Citadel class
- Citation
- Citation of Conspicuous Gallantry
- Cities of Refuge
- Cito
- Citron III
- City
- City Life
- City Oval
- City Watch
- City builder
- City of B'hala
- City of the Dead
- City of the Thousand Lights
- City on the Edge of Never
- Civeu
- Civil Conversation
- Civil Defense
- Civil Disobedience
- Civil Guard
- Civil war
- Civilian
- Civilian Assembly
- Civilian leader
- Civilian shuttle
- Civilian starship
- Civilization (episode)
- Civita
- Cl'cli'cl
- Cl'mntin
- Clado
- Clagg
- Claiborne Henry
- Claire
- Claire Eddy
- Claire Thorn
- Clamda
- Clampett
- Clan (Vulcan)
- Clan Briphachi
- Clan Ghe'Hara
- Clan Hgrtcha
- Clan Iggrazo
- Clan K'vek
- Clan Kaveth
- Clan McNee
- Clan Phelsht
- Clan Ru
- Clan Shaman
- Clan Wars
- Clan Wolf
- Clan nest
- Clan of Combat
- Clan of Enforcers
- Clan of the Eye
- Clancy
- Claneia
- Clanhaven 1
- Clapp (USS Enterprise-D)
- Clapshot
- Clara
- Clara (disambiguation)
- Clara Bernstein
- Clara Nieve
- Clara Nieve I
- Clare Raymond
- Claremont
- Clarinoxamine
- Clarion
- Clarissa Glenn
- Clarissa Nyn
- Clark
- Clark (Admiral)
- Clark (Captain)
- Clark (Ensign)
- Clark (Starbase 88)
- Clark (USS Defiant)
- Clark (medic)
- Clark (security)
- Clark Canyon
- Clark Colony
- Clark Dempsey
- Clark Dodson (23rd century)
- Clark Dodson (24th century)
- Clark Gable
- Clark Kent
- Clark Terrell
- Clark Terrell (Kelvin timeline)
- Clarke's Abyss
- Clarke's Disease
- Clarke's Star
- Clarke (Cadet)
- Clarke (Lieutenant)
- Clarke (shuttlecraft)
- Clarke class
- Clarke class (25th century)
- Clarus
- Clarus IV
- Clarus IX
- Clarze
- Clash on the Fire Plains
- Class-10 probe
- Class-1 probe
- Class-2 probe
- Class-3 probe
- Class-4 probe
- Class-5 probe
- Class-6 probe
- Class-7 probe
- Class-8 probe
- Class-9 probe
- Class 11 nebula
- Class 12 nebula
- Class 17 nebula
- Class 1 nebula
- Class 2 nebula
- Class 2 shuttlecraft
- Class 3 nebula
- Class 9 nebula
- Class A
- Class A gas giant
- Class A geothermal planet
- Class B
- Class B gas giant
- Class B geomorteus planet
- Class C
- Class C geoinactive planet
- Class C reducing planet
- Class C shuttlecraft
- Class D planet
- Class E planet
- Class F
- Class F geocrystalline planet
- Class F geometallic planet
- Class F planet
- Class F shuttlecraft
- Class G
- Class G geocrystalline planet
- Class G silicate planet
- Class H desert planet
- Class H shuttlecraft
- Class III
- Class III planet
- Class III starship
- Class II starship
- Class IV starship
- Class IX starship
- Class I gas supergiant
- Class I starship
- Class J
- Class J cargo ship
- Class J gas giant
- Class J nebula
- Class J starship
- Class K
- Class K nebula
- Class K silicate planet
- Class K transjovian planet
- Class L planet
- Class M
- Class MZ planet
- Class M (disambiguation)
- Class N
- Class N reducing planet
- Class O
- Class O planet
- Class P planet
- Class Q planet
- Class R
- Class R planet
- Class Reunion
- Class S-4 shuttlecraft
- Class S planet
- Class T
- Class T nebula
- Class T planet
- Class T technology
- Class VIII starship
- Class VII starship
- Class VI starship
- Class V starship
- Class XIII starship
- Class XII starship
- Class XIV starship
- Class XI starship
- Class XVI starship
- Class XV starship
- Class X starship
- Class Y
- Class Y planet
- Class clown
- Class of Excellence
- Claton Mintaine
- Clauda
- Claude
- Claude (disambiguation)
- Claude Fowler
- Claude Monet
- Claude Picard
- Claude Rains
- Claudia Alisov
- Claudia Balboni
- Claudia Kern
- Claudia Roque
- Claudia Schiffer
- Claudia Siguenza
- Claudine Robinson
- Claudius
- Claudius (Centurion class)
- Claudius (Cetratus class)
- Claudius (Gladius class)
- Claudius (Patronus class)
- Claudius (Securis class)
- Claudius Caecus
- Claudius Marcus
- Claudius Ptolemaeus
- Claustrophobia
- Clavius (disambiguation)
- Clavius Crater
- Clavius Mines
- Claw
- Claw (EDD-6)
- Claw of the Vindicator
- Clawfist
- Clawraker
- Claymare
- Claymore (carrier vessel)
- Claymore (disambiguation)
- Clayton
- Clayton (mirror)
- Cle Dan class
- Cleansing
- Cleante
- Cleante al-Faisal
- Clearsteel
- Clem Taplin
- Clements
- Clemons
- Clemons (Selva)
- Clemons (disambiguation)
- Cleo Severy
- Cleon
- Cleopatra
- Cleponji
- Cleric
- Clerics of Boreth
- Clev
- Cleveland
- Cleveland (disambiguation)
- Cleveland Booker
- Cleveland Indians
- Clia
- Clif
- Cliff
- Cliff Kennelly
- Cliff Myers
- Cliff Nielsen
- Clifford
- Clifford (disambiguation)
- Clifford Brent
- Clifford Wirth
- Cliffs of Bole
- Cliffs of Undalar
- Clifton Detzel
- Clint
- Clint Eastwood
- Clint Taylor
- Cloak
- Cloak & Dagger (Part 1)
- Cloak (clothing)
- Cloak (novel)
- Cloak and Dagger
- Cloak and Dagger, Part 2 of 2
- Cloak and Dagger (STO)
- Cloak and Dagger (duology)
- Cloak and Dagger (novel)
- Cloaker
- Cloaking band
- Cloaking device
- Cloaking frigate
- Clock
- Clone
- Closure
- Clothing
- Clothing by ?
- Clothing transporter
- CloudShape to-Ennien
- Cloud Walkers
- Cloud whale
- Clouseau Center
- Club Aknar
- Club Jove Adventure
- Clues
- Clumpship
- Cluros
- Clus
- Cluster Telpha-Z
- Cluster ship
- Cly'rana
- Clydesdale class
- Clytomenes
- Coal
- Coalescence
- Coalition Compact
- Coalition of Madena
- Coalition of Planets
- Coalition of Planets Security Council
- Coalsack
- Coamis
- Coaxial warp drive
- Cob'lat
- Cobalt
- Cobanian cigar
- Cobb
- Cobb (Commodore)
- Cobb (Doctor)
- Cobb salad
- Cobbins
- Cobh
- Cobol Blue
- Cobra
- Cobra-hawk
- Coburn
- Coburn (Admiral)
- Coburn (guide)
- Coca-Cola
- Cochise (disambiguation)
- Cochise class
- Cochrane
- Cochrane (Voyager shuttlecraft)
- Cochrane Center
- Cochrane Deceleration
- Cochrane Flyers
- Cochrane Foundation for the Study of Multiphysics
- Cochrane I
- Cochrane II
- Cochrane III
- Cochrane Institute of Alpha Centauri
- Cochrane Medal
- Cochrane Memorial
- Cochrane Research Facility
- Cochrane University of Applied Warp Physics
- Cochrane class (science vessel)