| Acronym | Definition |
|---|
| USSA | United Socialist States of America (book) |
| USSA | United States Ski and Snowboard Association |
| USSA | United States Sports Academy |
| USSA | United States Student Association |
| USSA | US Sportsmen's Alliance |
| USSA | US Sailing Association |
| USSA | United States Soccer Association |
| USSA | User Supported Software Association (United Kingdom) |
| USSA | United States Snooker Association (San Gabriel, CA) |
| USSA | United States Surfing Association |
| USSA | United States Surveyors Association |
| USSA | United States Security Authority for NATO Affairs |
| USSA | United States of South Africa (Arthur C. Clarke's book 2010) |
| USSA | United States Softball Association |
| USSA | United States Space Agency |
| USSA | Upper Shell Structure Assembly (US NASA) |