| Name | # Entries |
|---|---|
| Underwood | 970 |
| Upton | 832 |
| Urquhart | 807 |
| Usher | 523 |
| Unwin | 416 |
| Ung | 324 |
| Uren | 321 |
| Unger | 233 |
| Unsworth | 226 |
| Uddin | 217 |
| Underhill | 194 |
| Urban | 179 |
| Ure | 139 |
| Ullah | 131 |
| Upson | 105 |
| Underdown | 96 |
| Ulrich | 88 |
| Uppal | 86 |
| Urness | 69 |
| Ullrich | 67 |
| Utz | 53 |
| Upham | 49 |
| Ugarte | 44 |
| Udy | 43 |
| Urbano | 43 |
| Urbaniak | 41 |
| Utley | 37 |
| Uzzell | 36 |
| Urbanski | 35 |
| Uhrig | 33 |
| Ueda | 32 |
| Urrutia | 32 |
| Ullman | 32 |
| Upchurch | 31 |
| Urena | 30 |
| Uribe | 29 |
| Urbina | 28 |
| Ulbrich | 26 |
| Ulloa | 25 |
| Ulmer | 25 |
| Umali | 25 |
| Ungaro | 22 |
| Urso | 21 |
| Uchida | 21 |
| Uhl | 19 |
| Urie | 19 |
| Ulman | 18 |
| Umana | 17 |
| Ungar | 17 |
| Umlauf | 14 |
| Urbanczyk | 13 |
| Uhlman | 12 |
| Urbach | 12 |
| Urbanowicz | 11 |
| Ubaldo | 10 |
| Urbanek | 10 |
| Udell | 10 |
| Ullmann | 10 |
| Urizar | 8 |
| Ulm | 8 |
| Uriarte | 8 |
| Uhlig | 8 |
| Uehara | 7 |
| Uecker | 6 |
| Ugalde | 6 |
| Uher | 6 |
| Uber | 6 |
| Urquiza | 5 |
| Urzua | 5 |
| Uyeda | 4 |
| Urey | 3 |
| Urrea | 3 |
| Unser | 3 |
| Utt | 3 |
| Utter | 3 |