USG
- Ametek
- FN Five-seven
- Gamer Network
- K Koke
- Medical ultrasonography
- NowCast (air quality index)
- Ron Trent
- USG Corporation
- Ulysses S. Grant
- Under-Secretary-General of the United Nations
- Union Saint-Gilloise
- Unison Square Garden
- United States Government
- United States Guards
- Universities at Shady Grove
- University System of Georgia
- Unix Systems Group
- Urine specific gravity