| Nachname | Vorname |
| O'Brien | Flann |
| O'Brien | Tim |
| O'Gaora | Colm |
| O'Nan | Stewart |
| Oates | Joyce Carol |
| Oberg | F. C. |
| Oberholzer | René |
| Oberthanner | Ewald |
| Obradović | Aleksandar |
| Ocampo | Silvina |
| Ochoa | Rafael Menjívar |
| Oddsson | Davíð |
| Odoevskij | Vladimir |
| Oelker | Petra |
| Ofner | Dirk |
| Ogawa | Yôko |
| Oh | Jung-Hee |
| Ohlsen | Birgit |
| Okpanyi | Nora |
| Okri | Ben |
| Olaciregui | Julio |
| Olbracht | Ivan |
| Olguín | Sergio |
| Olsberg | Karl |
| Onetti | Juan Carlos |
| Onichimowski | Filip |
| Ool | Heinz-Josef van |
| Ooyen | Hans van |
| Oppliger | Cordelia |
| Örkény | István |
| Orlow | Wladimir |
| Orringer | Julie |
| Orsós | Jakab |
| Ortega Coto | Gregorio |
| Ortese | Anna Maria |
| Orths | Markus |
| Ortiz | Adalberto |
| Ortmeier | Martin |
| Osang | Alexander |
| Oskamp | Katja |
| Osmanović | Dijana |
| Ostermann | Hansjürgen |
| Ostermann | Irmgard Maria |
| Oswald | Jani |
| Otan | Majo |
| Otten | Birgit |
| Otten | Jürgen |
| Ottmann | Anton |
| Ovčina | Damir |
| Owen | Robert Charles |
| Özcan | Celal |
| Özdamar | Emine Sevgi |
| Özdogan | Selim |
| Ozick | Cynthia |
| Özlü | Demir |
| Özlü | Tezer |
| Özyalçıner | Adnan |
| Özyalçmer | Adnan |
| O’Brien | Edna |
| O’Connor | Bridget |
| O’Connor | Flannery |
| O’Connor | Frank |
| O’Faolain | Sean |
| O’Flaherty | Liam |