- Uckotter
- Uddin
- Uhl
- Uhlenbrock
- Uhling
- Uihlein
- Ujvary
- Ulland
- Ullett
- Ulliman
- Ullrich
- Ulm
- Ulmer
- Ulrich
- Umberg
- Underiner
- Underwood
- Ungar
- Unger
- Ungers
- Unnewehr
- Unthank
- Unwin
- Upchurch
- Updike
- Uphaus
- Upp
- Upshaw
- Upson
- Upthegrove
- Upton
- Urban
- Urbanek
- Urkew
- Urling
- Urriquia
- Ushry
- Utah
- Utecht
- Uth
- Utrup
- Uttrich
- Utz