| Name | Nation |
|---|---|
| O'Brien, Paidi | IRL |
| O'Grady, Stuart | AUS |
| O'Loughlin, David | IRL |
| O'Neill, Nathan | AUS |
| O'Reilly, Cody | USA |
| O'Shea, Glenn | AUS |
| Obando Brenes, Gregory | CRC |
| Oberholzer, Bernhard | SUI |
| Obst, Rene | GER |
| Ochoa, Carlos José | VEN |
| Ockeloen, Jasper | NED |
| Offredo, Yoann | FRA |
| Oh, Seong Youn | KOR |
| Ojavee, Mart | EST |
| Okada, Hiroyuki | JPN |
| Okrouhlicky, Tomas | CZE |
| Okunev, Denis | RUS |
| Olesen, Nicolaj | DEN |
| Oliphant, Evan | GBR |
| Oliveira, Helder | POR |
| Oliveira Amorim, Antonio Filipe | POR |
| Omloop, Geert | BEL |
| Omulec, Andrej | SLO |
| Ongarato, Alberto | ITA |
| Oostlander, Sander | NED |
| Opryshko, Oleg | UKR |
| Oredsson, Thomas | DEN |
| Orengo Lopez, Pascual | ESP |
| Oroz Ugalde, Juan Jose | ESP |
| Ortega Ocana, Manuel | ESP |
| Osiecki, Lukasz | POL |
| Osinski, Piotr | POL |
| Ospinoa, Enrique | COL |
| Oss, Daniel | ITA |
| Ostergaard, Niki | DEN |
| Othman, Muhamad Adiq Husainie | MAS |
| Ovechkin, Artem | RUS |
