| U América FC | Copa Perú | — | 1980 | Estadio Monumental U |
| U.S. Sangiorgese | — | — | — | — |
| Umana Venezia | — | — | 1925 | — |
| Unicar Cesena | — | Cesena | — | — |
| Unione Cestistica Piacentina | — | Piacenza | 2003 | — |
| Universitario de Trujillo | Copa Perú | — | July 10, 1965 | Estadio Mansiche |
| Universo Treviso Basket | Serie A | Treviso | 2012 | Palaverde |
| Unión Alfonso Ugarte | Copa Perú | — | 2003 | Estadio Jorge Basadre |
| Unión América | Copa Perú | — | — | Estadio Nacional del Perú (1897) |
| Unión Buenos Aires | — | — | 1917 | National Stadium of Peru |
| Unión Callao | Copa Perú | — | 1908 | Estadio Telmo Carbajo |
| Unión Carbone | Liga Regional de Lima y Callao | — | October 1925 | National Stadium of Peru |
| Unión Carolina | Copa Perú | — | 1905 | — |
| Unión Comercio | Peruvian Primera División | — | 1994 | Estadio IPD de Moyobamba |
| Unión Deportivo Ascensión | 2018 Copa Perú | — | July 18, 1959 | — |
| Unión Huaral | Copa Perú | — | 2020 | Estadio Julio Lores Colán |
| Unión Huayllaspanca | Copa Perú | — | 1983 | Estadio Huancayo |
| Unión Juventud | Copa Perú | — | August 22, 1956 | Estadio Manuel Rivera Sanchez |
| Unión Minas | Copa Perú | — | April 23, 1974 | Estadio Daniel Alcides Carrión |
| Unión Minas de Orcopampa | Copa Perú | — | January 8, 1980 | — |
| Unión Mirave | Copa Perú | — | 1977 | Estadio Jorge Basadre |
| Unión Ocopilla | Copa Perú | — | — | Estadio Huancayo |
| Unión Pesquero | Copa Perú | — | — | — |
| Unión Salaverry | Copa Perú | — | May 25, 1939 | Estadio Mariano Melgar |
| Unión San Martín | Copa Perú | — | — | — |
| Unión Supe | Copa Perú | — | October 12, 1954 | — |
| Unión Tarapoto | Peruvian Segunda División | — | 1955 | Estadio Carlos Vidaurre García |
| Utah Jazz | National Basketball Association | Salt Lake City | 1974 | Municipal Auditorium, Caesars Superdome, Loyola Field House, Delta Center, Salt Palace, Thomas & Mack Center |
| Utah Mammoth | — | — | 2024 | Delta Center |