| Abbreviation | Definition |
|---|---|
| SHT | Superior Hiking Trail |
| SHTML | Standford High Throwing Midget League |
| SHV | Schweizerischer Hängegleiter Verband |
| SHV | Sport Horse Versatility |
| SI | Sanctioned Individual |
| SI | Sport Influenced |
| SI | Sports Information |
| SI | Sports Injected |
| SI | Sports Injection |
| SIA | SnowSports Industries America |
| SIAC | Southern Intercollegiate Athletic Conference |
| SIC | Sepang International Circuit |
| SIC | Serious Injury Clan |
| SIC | Specializing In Competition |
| SICF | Slalom International Canoe Federation |
| SICG | Sydney Indoor Climbing Gym |
| SICK | Southern Indiana Crazy Kyakers |
| SID | Selfies Instants And Doubles |
| SID | Smad Interaction Domain |
| SIE | Self Induced Elimination |