USSI
| Acronym | Definition |
|---|---|
| USSI | Unione Stampa Sportiva Italiana (Italian: Italian Sports Press Union) |
| USSI | UnderSea Sensor Systems, Inc (Ultra Electronics; Columbia City, IN) |
| USSI | United Service Source, Inc. (Florida) |
| USSI | Universal Synchronous Serial Interface (Adtran Inc.) |
| USSI | United States Snowboard Instructors (Scarborough, ME) |
| USSI | Universal Software Solutions, Inc. (Davison, MI) |
| USSI | Utility Sealing Services, Inc. |