| Acronym | Definition |
|---|
| UFO | Unidentified Flying Object |
| UFO | Unified Film Organization |
| UFO | Undefined Fantastic Object (video game) |
| UFO | Unobtrusive Flash Objects |
| UFO | Unfinished Object |
| UFO | Unidentified Floating Object |
| UFO | Ultra High Frequency Follow-On (Navy satellite program) |
| UFO | Un Finished Object (related to crafts; knitting, quilting, etc.) |
| UFO | Unleaded Fuel Only |
| UFO | Unidentified Foreign Object |
| UFO | UHF Follow-On satellite |
| UFO | Universal Fibre Optics (consortium) |
| UFO | Until Further Order(s) |
| UFO | United Flying Octogenarians |
| UFO | Unidentified Fried Object (cafeteria slang) |
| UFO | Unavoidable Family Outing (Dave Hackett book) |
| UFO | Underwater Flying Object (from the movie 'The Abyss') |
| UFO | Unbelievably Fun Object (Megatech RC toy) |
| UFO | Ulead File Object (file extension) |
| UFO | Union Food Outlet |
| UFO | Universal Freight Organisation (Hampshire, England, UK) |
| UFO | USB FireWire Organizer |
| UFO | Unfolding and Partial Order Techniques (workshop) |
| UFO | Unified Font Object (XML-based font format) |
| UFO | Ubiquitous Findable Object |
| UFO | Unidentified Flowing Orifice (House; TV show) |
| UFO | Unidentified Floral Organs (Arabidopsis thaliana F-box protein) |
| UFO | Unfertilized Oocyte |
| UFO | Un-Filled Orders |
| UFO | Unidentified FMS Order |
| UFO | User Files On-Line |
| UFO | Universal Friendship Organization (Manipur) |
| UFO | Utregse Frisbee Organisation |
| UFO | Upgrade from Offline |