| Southwestern Intramural & Recreational Activities | Academic & Science |
| Solar Imaging Radio Array | Academic & Science |
| Scientific Informatics Research Academy | Academic & Science |
| Southern Indiana REALTORS Association | Business |
| Society of Information Risk Analysts | Business |
| Southern Indiana Radiological Associates | Business |
| Strategic Information Research Analysis | Business |
| State Insurance Regulatory Authority | Business |
| Shiba Inu Rescue Association | General |
| Sentra Informasi Referendum Aceh | General |
| Stable Isotope Ratio Analysis | General |
| Selective Integrated Reading Activity | General |
| Sentral Informasi Referendum Aceh | General |
| Systemic Infrastructure Resilience Analysis | General |
| Suspicion Indicators Recognition and Assessment | General |
| Societa Industriale Automotoristiche Ricerche | General |
| Association Senegalaise d'Importation de Representation Automobile | General |
| Sentral Informasi Referendum Aceh (Aceh Referendum Information Center) | Governmental |
| Securities Industry Regulatory Authority | Governmental |
| Security Industry Regulation Authority | Governmental |
| Security Industry Regulatory Authority | Governmental |
| SIRHILTARA | Indian Railway Station |
| Swedish International Relief Association | International |
| Strategic Industry Research Analysis | Military and Defence |
| Study In Rigional Australia | Regional |
| Simple Innovative Riding Accessory | Sports |
| Southern Indiana Racing Association | Sports |
| Southern Intercollegiate Rowing Association | Sports |
| Simple Innovative Riding Acces | Sports |
