| Abbreviation | Definition |
|---|---|
| UPL | United Pool League |
| UPLF | Unique Premier League Football |
| UPN | United Paramount Network |
| UPP | United Pro Players |
| UPW | Ultimate Pro Wrestling |
| UQ | Ultimate Quest |
| UQC | Ultimate Quad Capture |
| UQK | Ultimate Quik Kut & Polish (bowling) |
| UQS | United Quest Soccer |
| URA | Ultra Rage Attack |
| URC | United Racing Club |
| URD | U aRe Dead |
| URFA | Un- Restricted Free Agent |
| URL | U aRe Last |
| URM | Ultimate Racers Masters |
| URO | UnRoots Online |
| URPD | United Role Players Doctrine |
| URPW | Upper Rogue Pop Warner |
| URS | Un Restricted Sign |
| URT | Unified Rear Triangle (sport bikes) |