| Otl Aicher | Otl Aicher |
| Otocephaly | Octocefalia |
| Otocinclus | Otocinclus |
| Otok | Ilha |
| Otolith | Otólito |
| Otomat | Teseu |
| Otomi | Otomis |
| Otomi people | Otomis |
| otorhinolaryngologist | otorrino |
| Otoskopy | Otoscópio |
| Otranto | Otranto |
| Otrera | Otréra |
| Otsego County | Condado de Otsego |
| Ottaviano Nonni | Ottaviano Nonni |
| Ottavio Bottecchia | Ottavio Bottecchia |
| Ottawa | Otawa |
| Ottawa County | Condado de Ottawa |
| Ottawa Macdonald-Cartier International Airport | Aeroporto Internacional Ottawa Macdonald-Cartier |
| Ottawa Mcdonald-Cartier International Airport | Aeroporto Internacional Ottawa Macdonald-Cartier |
| Ottawa River | Rio Ottawa |
| Ottawa Senators | Ottawa Senators |
| Ottawa Treaty | Tratado de Ottawa |
| Ottenhofen | Ottenhofen |
| Ottenhöfen | Ottenhöfen |
| Ottensoos | Ottensoos |
| otter | lontra |
| Ottersweier | Ottersweier |
| Otterup municipality | Otterup |
| Otto | Oto da Baviera |
| Otto Binswanger | Otto Ludwig Binswanger |
| Otto Braun | Otto Braun |
| Otto Bütschli | Johann Adam Otto Bütschli |
| Otto Diels | Otto Paul Hermann Diels |
| Otto Dix | Otto Dix |
| Otto Finsch | Otto Finsch |
| Otto Friedrich Müller | Otto Friedrich Müller |
| Otto Fritz Meyerhof | Otto Fritz Meyerhof |
| Otto Hahn | Otto Hahn |
| Otto Heinrich Warburg | Otto Heinrich Warburg |
| Otto I | Sacro Imperador Romano-Germânico |
| Otto I of Guelders | Oto I da Grécia |
| Otto I of Nassau | Oto I da Grécia |
| Otto Jespersen | Otto Jespersen |
| Otto Kuntze | Carl Ernst Otto Kuntze |
| Otto Lilienthal | Otto Lilienthal |
| Otto Ludwig | Otto Ludwig |
| Otto Mann | Otto Mann |
| Otto Nordenskiöld | Otto Nordenskjöld |
| Otto of Bavaria | Oto da Baviera |
| Otto of Greece | Oto I da Grécia |
| Otto of Savoy | Oto da Baviera |
| Otto Preminger | Otto Preminger |
| Otto Skorzeny | Otto Skorzeny |
| Otto Stern | Otto Stern |
