| Olympic Mountains | Olympic Mountains |
| Olympic Oval | Olympic Oval |
| Olympie | Olympia |
| Olympiodore | Olympiodorus of Thebes |
| Olympiodore de Thèbes | Olympiodorus of Thebes |
| Olympiodore le jeune | Olympiodorus the Younger |
| Olympiodore le péripatéticien | Olympiodorus the Elder |
| Olympion | Temple of Olympian Zeus |
| olympique | Olympic |
| Olympique de Béja | Olympique Béja |
| Olympique de Khouribga | Olympique Khouribga |
| Olympique de Marseille | Olympique de Marseille |
| Olympique de Safi | Olympique Safi |
| Olympique lyonnais | Olympique Lyonnais |
| Olympiques | Olympics |
| Olympiques de Gatineau | Gatineau Olympiques |
| Olympiéion | Temple of Olympian Zeus |
| Olympos | Olympos |
| Olympus | Olympus Corporation |
| Olympus Mons | Olympus Mons |
| Oláibar | Oláibar |
| oléoduc | pipeline |
| Oléoduc Bakou-Tbilissi-Ceyhan | Baku-Tbilisi-Ceyhan pipeline |
| Oléoduc Druzhba | Druzhba pipeline |
| Oléoduc trans-Alaska | Trans-Alaska Pipeline System |
| oléographie | oleograph |
| Oléoplaste | Elaioplast |
| OMAC Project | The OMAC Project |
| Omaha | Omaha |
| Omaha Beach | Omaha Beach |
| Omake | Omake |
| Oman | Oman |
| Omar | Umar |
| Omar Al Mokhtar | Omar Mukhtar |
| Omar Al-Ghamdi | Omar Al-Ghamdi |
| Omar Bakri Muhammad | Omar Bakri Muhammad |
| Omar Ben Hafsun | Umar ibn Hafsun |
| Omar Bongo Ondimba | Omar Bongo |
| Omar Bradley | Omar Bradley |
| Omar el-Béchir | Omar al-Bashir |
| Omar Epps | Omar Epps |
| Omar ibn al-Khattab | Umar |
| Omar Karamé | Omar Karami |
| Omar Khayyam | Omar Khayyám |
| Omar Rodriguez-Lopez | Omar Rodríguez-López |
| Omar Sharif | Omar Sharif |
| Omar Sivori | Omar Sívori |
| Omar Torrijos | Omar Torrijos |
| Omar Troussier | Philippe Troussier |
| Omari Tetradze | Omari Tetradze |
