| Name | Nation |
|---|---|
| O'Bee, Kirk | USA |
| O'Donnell, Patrick | USA |
| O'Grady, Stuart | AUS |
| O'Loughlin, David | IRL |
| O'Neill, Nathan | AUS |
| Oarbeascoa Ispizua, Ruben | ESP |
| Obst, René | GER |
| Obwaller, Hans Peter | AUT |
| Odebrecht, Felix | GER |
| Odendaal, Jacobus | RSA |
| Odriozola Mugarza, Jon | ESP |
| Oegema, Bart | NED |
| Oelkers, Ryan | USA |
| Oeschger, Peter | SUI |
| Okazaki, Kazuya | JPN |
| Okrucinski, Daniel | POL |
| Oldin, Henrik | SWE |
| Oliveira, Ruben Fernandez | ESP |
| Olivier, Lénaïc | FRA |
| Olmo Menacho, Juan | ESP |
| Olson, Aaron | USA |
| Olsson, Jonas | SWE |
| Olszewski, Daniel | GER |
| Omloop, Geert | BEL |
| Ondryas, Richard | CZE |
| Ongarato, Alberto | ITA |
| Oouchi, Kaoru | JPN |
| Ordonez Citoula, Fernando | ESP |
| Ordowski, Volker | GER |
| Oriol, Christophe | FRA |
| Orvalho, David | NED |
| Osa Eizaguirre, Unai | ESP |
| Osa Eizaguirre, Aitor | ESP |
| Oschwald, Wolfgang | GER |
| Otero Gomez, Gustavo Miguel | ESP |
| Otto, Ronald | GER |
| Otto, Robert | GER |
| Oude Nyeweme, Niek | NED |
| Owczarek, Jonas | GER |
