Airlines — D
- DDAD & D Aviation
- DNKD&K Aviation
- DAODaallo Airlines
- DAGDagestan Airlines
- DHADahla Airlines
- DCSDaimler Chrysler Aviation
- DCXDaimler-Chrysler
- DKADaka
- DLRDala Air Services
- KHBDalavia
- DXPDallas Express Airlines
- DASDamascene Airways
- DANDan-Air London
- DSADanbury Airways
- DOPDancopter
- DAFDanish Air Force
- DARDanish Army
- DNYDanish Navy
- DNUDanu Oro Transportas
- DHEDAP Helicopteros
- DRTDarta
- DWTDarwin Airline
- DSRDAS Air Cargo
- RKCDAS Airlines
- DSQDasab Airlines
- DSHDash Air Charter
- GOBDash Aviation
- DGXDasnair
- DABDassault Aviation
- CVFDassault Falcon Jet Corporation
- DSODassault Falcon Service
- DTRDAT Danish Air Transport
- ENTDAT Enterprise Limited
- DTNData International
- XDTDate Transformation Corp
- DAUDauair
- DCODavid Crawshaw Consultants Limited
- DWNDawn Air
- DAYDaya Aviation
- DJSDayJet
- BAGdba
- DHCDe Havilland
- IAYDeadalos Flugtbetriebs
- DAADecatur Aviation
- DKNDeccan Aviation
- DLKDeccan Aviation (Lanka)
- DERDeer Jet
- JDCDeere and Company
- DWRDelaware Skyways
- DEADelta Aerotaxi
- SNODelta Air Charter
- ELJDelta Air Elite
- DALDelta Air Lines
- KMBDelta Engineering Aviation
- DLIDelta Express International
- DSUDelta State University
- DSYDennis Sky
- DWADense Airways
- DC2Dense Connection
- FECDenver Express
- DJTDenver Jet
- FGCDepartmento De Agricultura De La Generalitat De Cataluna
- BDNDERA Boscombe Down
- DRYDeraya Air Taxi
- DRXDes R Cargo Express
- MIZDesarrollo Milaz
- DSNDESNA
- DTYDestiny Air Services
- DETDETA Air
- DLTDeutsche Luftverkehrsgesellschaft
- DWDDeutsche Luftverkehrsgesellschaft (DLT)
- AMBDeutsche Rettungsflugwacht
- LFODeutsches Zentrum fur Luft-und Raumfahrt EV
- DXTDexter (DXT)
- VLFDFS UK Limited
- DGODGO Jet
- DAEDHL Aero Expreso
- DHKDHL Air
- DHVDHL Aviation
- JOSDHL de Guatemala
- DHXDHL International
- DISDi Air
- SPKDiamond Aviation
- DRBDidier Rousset Buy
- DGTDigital Equipment Corporation
- RDNDinar
- DIPDiplomatic Freight Services
- ENADireccion General de Aviacion Civil y Telecomunicasciones
- DSVDirect Aero Services
- DIADirect Air
- XAPDirect Air trading as Midway Connection
- DCTDirect Flight
- DIRDirgantara Air Service
- DCVDiscover Air
- DVADiscovery Airways
- XDSDispatch Services
- DIXDix Aviation
- DEEDixie Airways
- DJBDjibouti Airlines
- GPLDLR