- Siem Reap Airways
- Silk Way Airlines
- SilkAir
- Silverjet
- Sita Air
- Sky Airline
- Skymark Airlines
- Skytrans Airlines
- Skyways Express
- Skywest Airlines
- Slok Air Gambia
- SonAir
- Sounds Air
- Song Airlines
- South African Express
- South East Asian Airlines
- Star Aviation
- Star Peru
- Stewart Island Flights
- Sunexpress
- SVG Air
- Swaziland Airlink
- Swiftair
- Swiss European Air Lines
- Sylt Air
