| Abbreviation | Definition |
|---|---|
| STS | Shuttle Train Services |
| STS | Shuttle Transportation System |
| STS | Space Transportation System |
| STS | Special Transportation Service |
| STS | Sport Touring Sedan |
| STS | Super Transportation System |
| STSO | Supervisor Transportation Security Officer |
| STSO | Supervisory Transportation Security Officer |
| STSP | Strategic Transportation Safety Plan |
| STSP | Sustainable Transportation Systems Program |
| STT | Cyril E King Airport |
| STT | Short Term Trip |
| STTC | Surface Transportation Technical Committee |
| STTS | Safe Transportation Training Specialists |
| STURAA | Surface Transportation and Uniform Relocation Assistance Act - 1987 |
| STV | Single Transferable Vote |
| SU | Speed Up |
| SUA | Special Use Airspace |
| SUAVE | Sport Utility Assault Vehicle Extreme |
| SUAVS | Small Unmanned Aerial Vehicle System (for wildlife radio collar tracking) |