| Acronym | Definition |
|---|
| USI➣University of Southern Indiana |
| USI➣USinternetworking, Inc. (Annapolis, MD) |
| USI➣Union of Students in Ireland |
| USI➣Unité de Santé Internationale (French: International Health Unity; Canada) |
| USI➣User Service Information |
| USI➣Universal Sim Interface |
| USI➣User Specific Interface |
| USI➣Usb Interface |
| USI➣United Stationers, Inc. (Deerfield, IL) |
| USI➣Universal Salt Iodization (WHO/UNICEF) |
| USI➣Urban Systemic Initiative |
| USI➣Urban School Improvement |
| USI➣Universidad de Sta Isabel (Naga City, Philippines) |
| USI➣User System Interface (Alcatel) |
| USI➣Universal Systems, Inc. |
| USI➣United Submitters International (religious group) |
| USI➣Ultrasonic Systems Inc (Haverhill, MA) |
| USI➣Utility Services, Inc. (subsidiary of MDU Resources Group) |
| USI➣Ultrasonic Imaging |
| USI➣Unresolved Safety Issue |
| USI➣Unwarranted Self-Importance (Internet slang) |
| USI➣Universal Swap Identifier (financial regulations) |
| USI➣User Service Information (ITU-T) |
| USI➣Union Sportive d'Ivry (French sports club) |
| USI➣United Schools International (Indonesia) |
| USI➣Universal Scanner Interface |
| USI➣Unique Secondary Index |
| USI➣US Interactive, Inc |
| USI➣ULANA Service Interface |
| USI➣Uniform Side-Information |
| USI➣União de Sindicatos Independentes (Portugese: Union of Independent Trade Unions) |
| USI➣Unione Sidacale Italiana (Italian: Italian Workers Union) |
| USI➣Universal System Identifier (US DoD) |