| Abbreviation | Definition |
|---|---|
| UKH | United Kingdom Hockey |
| UKJ | U K Judo |
| UKK | Universitetets KarateKlubb |
| UKL | United Kapz League |
| UKO | Universal Kickboxing Organization |
| UKPA | United Kingdom Polocrosse Association |
| UKPPG | United Kingdom Powered Para Gliding |
| UKSA | United Kingdom Sports Academy (now simply UKSA) |
| UKU | United Kingdom Ultimate sports |
| UKW | United Kingdom Wrestling |
| ULA | UltraLight Adventure |
| ULE | UltraLight Equipment |
| ULI | Ultra-Light Inflatable (surfboards) |
| ULT | ULTimate |
| UM | Ultra Maniac |
| UM | Undefeated Masters |
| UM | Utter Madness |
| UMAC | Upper Merion Aquatic Club |
| UMAD | University of Memphis Athletic Department |
| UMECRA | Upper Midwest Endurance and Competitive Rides Association |