| Abbreviation | Definition |
|---|---|
| USO | United Service Organization |
| USP | Underground Siege Project |
| USP | Universal Selbstlade Pistole |
| USP | Universal Silenced Pistol |
| USP | Universelle SelbstladePistole |
| USPACAF | United States PACific Command Air Forces |
| USPACFLT | United States PACific Fleet |
| USPACOM | United States PACific COMmand |
| USPFO | United States Property and Fiscal Officer |
| USPFO(P&C) | United States Property and Fiscal Office (Purchasing and Contracting) |
| USPHS | United States Public Health Service |
| USR | Unit Status Report |
| USR | United Sniper Regiment |
| USRD | Underwater Sound Reference Division, Naval Undersea Warfare Center |
| USREPMC | United States REPresentative to the NATO Military Committee |
| USS | United Seamen's Service |
| USS | United States Ships |
| USSBS | United States Strategic Bombing Survey |
| USSC | United States Signal Corps |
| USSF | United States Special Forces |