| Acronym | Definition |
|---|
| SIU➣Southern Illinois University |
| SIU➣Special Investigations Unit |
| SIU➣Suck It Up! |
| SIU➣Seafarers International Union |
| SIU➣Source Interface Unit |
| SIU➣Station Interface Unit |
| SIU➣Special Investigative Unit |
| SIU➣School Improvement Unit (various locations) |
| SIU➣Société Internationale d'Urologie (French: International Society of Urology) |
| SIU➣Schiller International University |
| SIU➣Salem International University |
| SIU➣Significant Industrial User |
| SIU➣Sapporo International University (Japan) |
| SIU➣System Interface Unit |
| SIU➣Senter for internasjonalisering av høyere utdanning (Centre for International University Cooperation; Norway) |
| SIU➣Societá Italiana di Urologia |
| SIU➣Signal Interface Unit |
| SIU➣Senter for Internasjonalt Universitetssamarbeid (Norwegian: Centre for International University Cooperation) |
| SIU➣Serial Interface Unit |
| SIU➣Système Intra-Utérin (French: Intrauterine System) |
| SIU➣System Integration Unit |
| SIU➣Southern Insurance Underwriters, Inc. (Georgia and Florida) |
| SIU➣Sensitive Investigative Unit |
| SIU➣Sets In Use (TV) |
| SIU➣Service Informatique Universitaire (French: University Computing Services; University of Namur; Belgium) |
| SIU➣Scheduling Information Unsolicited (health care) |
| SIU➣Simulation Interface Unit (US DoD) |
| SIU➣Société d'Imagerie Ultrasonore (French: Ultrasonic Imaging Society) |
| SIU➣Sudan International University (Khartoum, Sudan; est. 1990) |
| SIU➣Storage Interface Unit |
| SIU➣Sinyal Isleme, Iletisim Ve Uygulamalari Kurultayi (Turkish) |
| SIU➣Slide in Unit |
| SIU➣Secondary Index Utility |
| SIU➣Subsystem Interface Unit |
| SIU➣Sector Intelligence Unit (US Border Patrol) |
| SIU➣Special Investigative University (Colorado Springs, CO) |
| SIU➣Synchronization Interval Unit |