| Crew | City | Country | Started in |
|---|---|---|---|
| Ugly Duckling | — | United States | 1990s |
| Ukendt Kunstner | — | — | 2010s |
| Ultramagnetic MCs | New York City | United States | 1980s |
| UNB | Seoul | — | 2010s |
| Undergrunn | Oslo | — | 2010s |
| UNNV | Minsk | — | 2010s |
| Untouchable | — | — | 2000s |
| Upsurt | — | — | 1990s |
| Urban Dance Squad | — | Netherlands | 1980s |
| UTFO | New York City | — | 1980s |
| Úlfur Úlfur | — | Iceland | 2010s |