| Crew | City | Country | Started in |
|---|---|---|---|
| Odezenne | Bordeaux | — | — |
| One-T | — | — | 2000s |
| ONF | Seoul | — | 2010s |
| Orelha Negra | Lisbon | — | 2000s |
| Organized Konfusion | — | — | 1980s |
| Organized Noize | Atlanta | — | 1990s |
| Originoo Gunn Clappaz | New York City | — | 1990s |
| Orishas | Havana | — | 1990s |
| Osdorp Posse | Amsterdam | — | 1980s |
| Otpetye Moshenniki | Saint Petersburg | — | 1990s |
| OutKast | — | United States | 1990s |
| Outlandish | — | — | 1990s |
| Outlawz | — | United States | 1990s |