Airlines — S
- HAUSkyhaul
- SEKSkyjet
- SJUSkyjet Airlines
- SKISkyking
- SKISkyKing Turks and Caicos Airways
- SMTSkyline
- SKNSkyline Aviation Services
- KCUSkyline Ulasim Ticaret A.S.
- SKKSkylink Aviation
- SKYSkymark Airlines
- SKCSkymaster Air Lines
- SDDSkymaster Air Taxi
- SIHSkynet Airlines
- SNJSkynet Asia Airways
- XXSSkyplan Services
- EANSkypower Express Airways
- HRISkyraidybos Mokymo Centras
- WLKSkyrover CC
- SKRSkyscapes Air Charters
- SSVSkyservice Airlines
- SKTSkystar Airways
- SSKSkystar International
- IGASkytaxi
- SYXSkywalk Airlines
- SGKSkyward Aviation
- SKZSkyway Enterprises
- SYASkyways
- SKXSkyways Express
- SKWSkyWest
- OZWSkywest Airlines
- SPCSkyworld Airlines
- SYJSlate Falls Airways
- SHXSlim Aviation Services
- SLNSloane Aviation
- SLBSlok Air
- OKSSlok Air Gambia
- SQFSlovak Air Force
- SLLSlovak Airlines
- SSGSlovak Government Flying Service
- SQASlovak National Aeroclub
- SIVSlovenian Armed Forces
- SMASMA Airlines
- SMFSmalandsflyg
- ELCSmall Planet Airlines
- USNSmarkand Aero Servise
- SMLSmith Air (1976)
- SMHSmithair
- SBQSmithkline Beacham Clinical Labs
- RSESNAS Aviation
- SBDSnowbird Airlines
- SNUSnunit Aviation
- SBLSobel Airlines of Ghana
- KOLSOCHI AIR
- QERSOCHI AIR CHATER
- SAESOCHI AIR EXPRESS
- SNSSociete Centrafricaine De Transport Aerien
- NSCSociete De Transport Aerien De Mauritanie
- TTMSociete Tout Tranport Mauritanien
- SCFSocofer
- OKTSoko Aviation
- PIVSokol
- OLSSol Lineas Aereas
- SRBSolar Air
- OLCSolar Cargo
- SFUSolent Flight
- SOXSolid Air
- SOPSolinair
- OLOSoloflight
- SOLSolomon Airlines
- SOMSomali Airlines
- SMRSomon Air
- SORSonair Servico Aereo
- SYISonalysts
- ONGSonnig SA
- STISontair
- SNLSoonair Lines
- SAGSOS Flygambulans
- MCGSOS Helikoptern Gotland
- OSLSosoliso Airlines
- LMGSouth African Air Force
- SAASouth African Airways
- EXYSouth African Express
- SYYSouth African Historic Flight
- SCSSouth African Non Scheduled Airways
- OTLSouth Airlines
- SCNSouth American Airlines
- BDSSouth Asian Airlines
- PLTSouth Carolina Aeronautics Commission
- SCASouth Central Air
- GADSouth Coast Aviation
- SRQSouth East Asian Airlines
- SPISouth Pacific Island Airways
- SWCSouth West Air
- STWSouth West Air Corporation
- SEASoutheast Air
- SNKSoutheast Airlines (Sun Jet International)
- SPUSoutheast Airmotive
- SOTSoutheast Correct Craft
- SXESoutheast Express Airlines
- PTMSoutheastern Airways