| Oh ladies running club | 45 | View |
| Okehampton Cycling Club | 39 | View |
| Okehampton Running Club | 121 | View |
| Okhane | 1 | View |
| Old Hatfield Ladies Running Club | 24 | View |
| Old Place Football Team (老地方足球队） | 1 | View |
| Old Portlians CC | 6 | View |
| Oldham & Royton Harriers | 20 | View |
| Oldham and Royton Harriers and Athletics club | 40 | View |
| Oldham&Royton HarriersAC | 7 | View |
| Olive Trailblazers | 5 | View |
| Olive tree trailblazers | 6 | View |
| Oliver Brown | 0 | View |
| Oliver Lester | 0 | View |
| Oliver Way | 0 | View |
| Olivier Serviable | 1 | View |
| Olki | 1 | View |
| Ollie Harrison | 1 | View |
| Olney Runners | 54 | View |
| Omagh Harriers | 3 | View |