Airlines — C
- HSECompania Helicopteros Del Sureste
- MDRCompania Mexicana De Aeroplanos
- MXCCompania Mexicargo
- HSSCompania Transportes Aereos Del Sur
- CYFCompany Flight
- CPZCompass Airlines
- CYMCompass Airlines (Australia)
- CPSCompass International Airways
- XCOCompuflight Operations Service
- XCSCompuserve Incorporated
- COEComtel Air
- CRCConair Aviation
- CODConcordavia
- CIBCondor
- CNRCondor Aero Services
- CFGCondor Flugdienst
- COFConfort Air
- CAKCongo Air
- CGACongressional Air
- ROYConifair Aviation
- CBYConingsby Flying Training Unit
- BSNConnectair Charters
- 2COConneX European Airline
- CACConquest Airlines
- CXOConroe Aviation Services
- CHPConsorcio Aviaxsa
- VCHConsorcio Helitec
- UZAConstanta Airline
- KISContact Air
- XCLContel ASC
- COAContinental Airlines
- PVVContinental Airways
- CMIContinental Micronesia
- CONContinental Oil
- VCVConviasa
- CKACook Inlet Aviation
- SVYCooper Aerial Surveys
- CMPCopa Airlines
- CATCopenhagen Airtaxi
- CX0Copenhagen Express
- COPCopper State Air Service
- AAQCopterline
- CCWCoptrade Air Transport
- CAICorendon Airlines
- CRACoronado Aerolineas
- CPBCorpac Canada
- CNCCorporacion Aereo Cencor
- CPGCorporacion Aeroangeles
- CGYCorporacion Paraguaya De Aeronautica
- CPRCorporate Air
- CPOCorporate Aircraft Company
- COOCorporate Airlink
- CKECorporate Aviation Services
- VHTCorporate Flight International
- VTECorporate Flight Management
- CJICorporate Jets
- CRLCorsairfly
- CCMCorse-Mediterranee
- COZCosmic Air
- COTCottesmore Flying Training Unit
- CHICougar Helicopters
- MGBCoulson Flying Service
- NSWCountry Connection Airlines
- CIKCountry International Airlines
- CSDCourier Services
- CUTCourt Helicopters
- CVLCoval Air
- COWCowi
- COYCoyne Aviation
- CFDCranfield University
- CWLCranwell Flying Training Unit
- CRECree Airways
- ELMCrelam
- CANCrest Aviation
- CRHCRI Helicopters Mexico
- KRMCrimea Universal Avia
- CTNCroatia Airlines
- HRZCroatian Air Force
- CRXCross Aviation
- ECCCrossair Europe
- CWXCrow Executive Air
- CKRCrown Air Systems
- CROCrown Airways
- CRWCrownair
- VCRCruiser Linhas Aereas
- CRZCruzeiro do Sul Servicos Aereos
- CTYCryderman Air Service
- CYTCrystal Shamrock
- IROCSA Air
- CSECSE Aviation
- CTQCTK Network Aviation
- CUBCubana de Aviación
- CBLCumberland Airways (Nicholson Air Service)
- CTTCustom Air Transport
- RGNCygnus Air
- CYCCyprair Tours
- CYSCypress Airlines
- CYPCyprus Airways
- CEFCzech Air Force
- AHDCzech Air Handling