| U&L | Upper And Lower 
| Others |
| U/L | Units per Liter
| Others |
| U/L | Uplink
| Others |
| U/L | Uplink (UPLK preferred)
| Others |
| U/L | UpLoading
| Others |
| UL | ULAW Music file
| Others |
| UL | Ultra Latency
| Others |
| UL | Ultra Light
| Others |
| UL | Ultra Lite
| Others |
| UL | Ultra Loader
| Others |
| UL | Ultronix
| Others |
| UL | UnderLoad
| Others |
| UL | Underwire Layer
| Others |
| UL | Underwriter Laboratories
| Others |
| UL | Underwriter Laboratory, a U.S. government agency that controls and monitors lighting rules and safety
| Others |
| UL | Underwriters Laboratories
| Others |
| UL | Underwriters Laboratories, Inc.
| Others |
| UL | Underwriters Laboratory
| Others |
| UL | Underwriters Laboratory/ies
| Others |
| UL | Underwriters Labratories
| Others |
| UL | Unexplored Land
| Others |
| UL | Unhemmed Length
| Others |
| UL | Unilever
| Others |
| UL | Unit Leader
| Others |
| UL | Unit Level
| Others |
| UL | United Laboratories
| Others |
| UL | Universal Library
| Others |
| UL | Universal Life
| Others |
| UL | Universal Locator
| Others |
| UL | University of Leiden
| Others |
| UL | University of Limerick (Ireland)
| Others |
| UL | University of Lisbon
| Others |
| UL | University of Louisiana
| Others |
| UL | University of Louisville
| Others |
| UL | University of Louisville (Kentucky)
| Others |
| UL | Unnumbered List
| Others |
| UL | Unordered List
| Others |
| ul | Unordered Lists
| Others |
| UL | Unorganized List
| Others |
| UL | Unpaid Leave
| Others |
| UL | Unsigned Long
| Others |
| UL | Unsorted List
| Others |
| UL | Unwritten Law
| Others |
| UL | Up Left
| Others |
| UL | Upload
| Others |
| UL | Uppaal Language
| Others |
| UL | Upper Left
| Others |
| UL | Upper Level
| Others |
| UL | Upper Limb
| Others |
| UL | Upper Limit
| Others |
| UL | Upper Lobe
| Others |
| UL | Urban Legend
| Others |
| UL | Used List
| Others |
| UL | Using Linux
| Others |
| UL | Utterly Lazy
| Others |
| UL | Utterly Legal
| Others |