| Acronym | Definition |
|---|
| USA | United States of America |
| USA | United States Army |
| USA | USA Network (cable network channel) |
| USA | University of South Alabama |
| USA | University of South Australia |
| USA | United States Attorney |
| USA | United Space Alliance |
| USA | United Soccer Association (Florida) |
| USA | United Soccer Academy |
| USA | Union of South Africa |
| USA | Unstable Angina |
| USA | Underground Service Alert |
| USA | Uniform System of Accounts |
| USA | US Airways, Inc. (ICAO code) |
| USA | United Synagogue of America |
| USA | United States of Africa (Arthur C. Clarke's '3001') |
| USA | Under Secretary of the Army |
| USA | Unified Shader Architecture |
| USA | United Scenic Artists |
| USA | United Seniors Association |
| USA | United Stockgrowers of America |
| USA | Uniform Securities Act |
| USA | Universal Secure Access (Universal Secure Access Card Identifier) |
| USA | Urban Service Area |
| USA | Utah State Archives |
| USA | Unconditional Self-Acceptance |
| USA | Universal Service Agency (South Africa) |
| USA | Unionville-Sebewaing Area (Michigan School District) |
| USA | Unicycling Society of America |
| USA | Unix System Admin |
| USA | You Suck Ass |
| USA | United States of Atlanta (Ying Yang Twins album) |
| USA | Universal Surety of America (Dallas, TX) |
| USA | Unit Self Assessment (US Navy) |
| USA | Unconventional Stellar Aspect |
| USA | United Software Association |
| USA | Unusually Sensitive Area (environmental) |
| USA | United States Armsports |
| USA | Universities Safety Association |
| USA | Union Street Athletics (Bangor, Maine) |
| USA | Ulhasnagar Sindhi Association |
| USA | Underwriting Service Assistant (insurance) |
| USA | Upsilon Sigma Alpha (honor society) |
| USA | Under Skirt Area |
| USA | Ultimate in Suspense and Action |
| USA | United Secularists of America, Inc. |
| USA | United Servicers Association, Inc. |
| USA | Underground Sewer Adapter |
| USA | Utilization, Support, & Accountability |
| USA | United Sites of America, Inc. |
| USA | Uninterrupted Sharing Activity (education/reading) |
| USA | Unique Settable Attributes (Ciena) |
| USA | United Spirit Arena (Texas) |
| USA | United Shooter's Association (Thornton, CO) |