| Abbreviation | Definition |
|---|---|
| UNSG | United Nations Secretary-General |
| UNSOC | United Nations Staff Officers Course |
| UNT | Unified Networking Technology |
| UNTAC | United Nations Transition Authority In Cambodia |
| UNTDS | Unit Description (Parent) |
| UNTSO | United Nations Truce and Supervision Organization |
| UNV | United Nations Volunteer |
| UO | Unidentified Object |
| UO | Uniformed Organisations |
| UO | Until Obsolete |
| UO(s) | Uniformed Officer(s) |
| UOB | Unit Order Of Battle |
| UOD | Uniform Of The Day |
| UOES | User Operational Evaluation System |
| UOF | Use of Force |
| UOH | Unity Of Honor |
| UONS | Urgent Operational Need Statement |
| UOO | Unit Of Operations |
| UOQ | Unaccompanied Officers Quarters |
| UOQ | Unit of Quantity |