Airlines — S
- SOOSouthern Air
- SOASouthern Air Charter
- SOUSouthern Airways
- LTDSouthern Airways Express
- SOISouthern Aviation
- SOCSouthern Cargo Air Lines
- SXASouthern Cross Aviation
- SFSSouthern Frontier Air Transport
- ALCSouthern Jersey Airways
- SOHSouthern Ohio Aviation Sales
- SGCSouthern Right Air Charter
- SSCSouthern Seaplane
- SWDSouthern Winds Airlines
- SFLSouthflight Aviation
- SJSSouthjet
- XANSouthjet cargo
- ZCSSouthjet connect
- XPGSouthport Air Service
- SWASouthwest Airlines
- SOWSowind Air
- SPFSpace World Airline
- JKKSpanair
- AMESpanish Air Force
- BXSSpantax S.A.
- THBSpark Air
- BVVSpark+ Joint-Stock Company
- SPSSPASA
- BHVSpecavia Air Company
- SYVSpecial Aviation Systems
- SSOSpecial Scope Limited
- SSZSpecsavers Aviation
- CDSSpectrem Air
- XSASpectrum Air Service
- LSPSpectrum Aviation Incorporated
- SPTSpeed Aviation
- SPWSpeedwings
- SEJSpicejet
- SALSpike Airlines
- NKSSpirit Airlines
- SJJSpirit Aviation
- SDNSpirit of Africa Airlines
- MNPSpirit of Manila Airlines
- WCCSport Air Travel
- SPESprague Electric Company
- CQHSpring Airlines
- SJOSpring Airlines Japan
- SAQSpringbank Aviation
- SPBSpringbok Classic Air
- SPGSpringdale Air Service
- SRNSprintair
- ASLSpurling Aviation
- PURSpurwing Airlines
- ALKSriLankan Airlines
- SJYSriwijaya Air
- SDASt. Andrews Airways
- SVDSt. Vincent Grenadines Air (1990)
- SBASTA-MALI
- SBOStabo Air
- SOBStabo Freight
- SGFSTAC Swiss Government Flights
- STCStadium City Limited
- STLStapleford Flight Centre
- STUStar African Air
- STAStar Aviation
- SFJStar Flyer
- SSDStar Service International
- SRUStar Up
- SUUStar West Aviation
- SWPStar Work Sky
- GXLStar XL German Airlines
- HCWStar1 Airlines
- BLYStarair
- SLFStarfly
- STSStarling Airlines Spain
- TRLStarlite Aviation
- STXStars Away Aviation
- HIPStarship
- SSPStarspeed
- BECState Air Company Berkut
- UFAState Flight Academy of Ukraine
- NEBState of Nebraska
- SUMState Unitary Air Enterprise
- SWJStateswest Airlines
- STBStatus-Alpha Airline
- SBBSteinman Aviation
- SLVStella Aviation
- XSNStephenville Aviation Services
- SNBSterling Airlines
- SVHSterling Helicopters
- YBEStewart Aviation Services
- VGSStichting Vliegschool 16Hoven
- STPSTP Airways
- SRZStrato Air Services
- SLEStreamline
- SSWStreamline Aviation
- STOStreamline Ops
- FFDStuttgarter Flugdienst
- STYStyrian Airways
- SUBSuburban Air Freight
- SDUSud Airlines