| Abbreviation | Definition |
|---|---|
| UDP | User Datagram Protocol |
| UDR | Ulster Defence Regiment |
| UDR | Unidades de Detecção de Raios |
| UDR | Unit Decay Rate |
| UDR-13 | Pocket Radiac Set |
| UDS | Ultimate Death Squad |
| UDS | Unit Data System |
| UDT | Un-armed Defensive Tactic |
| UDT | Underwater Demolition Team |
| UDT | Underwater Demolition Teams |
| UDU | Underwater Demolition Unit |
| UE | Unit Equipment |
| UE | United Endeavor (exercise) |
| UE | User Equipment |
| UEDP | UTACCS (USAREUR Tactical Army Command and Control System) Evolutionary Development Plan |
| UEM | Used Equipment Marketplace |
| UES | Unified Energy System |
| UET | Unit Execution Time |
| UET | Universal Engineer Tractor |
| UEU | Upper Electronics Unit |