Airlines — C
- CUAChina United Airlines
- CXHChina Xinhua Airlines
- CGUChinguetti Airlines
- CEPChipola Aviation
- CPWChippewa Air Commuter
- CHFChitaavia
- CSXChoice Airways
- CQNChongqing Airlines
- CASChristman Air System
- OECChristophorus Flugrettungsverein
- CHOChrome Air Services
- CHUChurch Aircraft
- CFNChurch Fenton Flying Training Unit
- VCICI-Tours
- YCCCiel Canadien
- CIUCielos Airlines
- CIMCimber Air
- RRUCirrus
- NTSCirrus Air
- RUSCirrus Airlines
- JTICirrus Middle East
- FIVCitationshares
- XCXCitibank
- HZXCitic General Aviation
- SDRCity Airline
- GTACity Airways
- CIXCity Connexion Airlines
- XBGCity of Bangor
- CIPCity-Air Germany
- CAQCityair (Chester) Limited
- CIICityfly
- BCYCityJet
- CNBCityline Hungary
- HSRCitylink Airlines
- CIWCivair Airways
- BKRCivil Air Patrol South Carolina Wing
- CATCivil Air Transport
- CIACivil Aviation Authority
- CIVCivil Aviation Authority of New Zealand
- CBACivil Aviation Inspectorate of the Czech Republic
- CKCCKC Services
- FMCClaessens International Limited
- CLKClark Aviation
- CSFClasair
- CLYClay Lacy Aviation
- CGKClick Airways
- CLZCloud 9 Air Charters
- CLDClowes Estates Limited
- SDJClub 328
- ISGClub Air
- CMZCM Stair
- CNTCNET
- OAPCOAPA AIR
- CSTCoast Air
- TCLCoastal Air Transport
- CNGCoastal Airways
- CSVCoastal Travels
- FCBCOBALT
- CHLCohlmia Aviation
- OLRColaereos
- CLEColemill Enterprises
- CJCColgan Air
- CAEColibri Aviation
- CCXColt International
- COHColtishall Flying Training Unit
- COLColumbia Airlines
- WCOColumbia Helicopters
- KLRColumbus Air Transport
- GHPColvin Aviation
- CAWComair
- PDRCOMAV
- CDEComed Group
- CVVComeravia
- CRSComercial Aerea
- CMGComet Airlines
- FYNComfort Air
- CEOComfort Express Virtual Charters
- EVCComfort Express Virtual Charters Albany
- CLAComlux Aviation
- CMHCommair Aviation
- CTMCommandement Du Transport Aerien Militaire Francais
- CMLCommander Air Charter
- CRMCommander Mexicana
- CMSCommercial Aviation
- GARCommodore Aviation
- CJSCommonwealth Jet Service
- UCACommutAir
- CWKComores Airlines
- CGRCompagnia Generale Ripreseaeree
- CMMCompagnie Aerienne du Mali
- GICCompagnie de Bauxites de Guinee
- CPMCompagnie Mauritanienne Des Transports
- BFNCompangnie Nationale Naganagani
- AIFCompania Aerea de Valencia
- ATFCompania Aerotecnicas Fotograficas
- ASUCompania Boliviana de Transporte Aereo Privado Aerosur
- LCTCompania De Actividades Y Servicios De Aviacion
- CFPCompania de Aviacion Faucett
- TAVCompania de Servicios Aereos Tavisa
- EJVCompania Ejecutiva