| Oskar Wadyslaw De Lubicz Milosz |
| Oskar Wadyslaw De Lubicz Mislosz |
| Ossip Emilievitch Mandelstam |
| Ossip Mandelstam |
| Ostad Elahi |
| Oswald Mbuyiseni Mtshali |
| Oswald Spengler |
| Othman Ibn Affan |
| Otomo No Yakamochi |
| Otto Manninen |
| Otto Rank |
| Otto Von Bismarck |
| Otto Weininger |
| Ou-tsé |
| Ousmane Diop Socé |
| Ousmane Sembène |
| Oussama ben Laden |
| Oven Arnold |
| Ovide |
| Owen Feltham |
| Owen Meredith |
| Owen Young |
| Ozzy Osbourne |