| Club | League | Based in | Founded | Home ground |
|---|---|---|---|---|
| Uhrik Truckers | American Soccer League | Philadelphia | 1933 | — |
| Ukrainian Sports Club NY | Cosmopolitan Soccer League | — | 1947 | — |
| Union Omaha | USL League One | Omaha | 2019 | — |
| Unique FC | St Croix Soccer League | — | 1970 | — |
| USL Chicago | USL Championship | Chicago | November 21, 2017 | Lincoln Yards Stadium |
| Utah Blitzz | USL Second Division | Salt Lake City | 2000 | Rice–Eccles Stadium |
| Utah Golden Spikers | American Soccer League | Salt Lake City | 1976 | — |
| Utah Salt Ratz | National Premier Soccer League | Salt Lake City | 2003 | Rice–Eccles Stadium |
| Utica City FC | Major Arena Soccer League | — | 2010 | Oncenter War Memorial Arena |
| Utulei Youth | — | Utulei | 1996 | Veterans Memorial Stadium |