| Otawa | Ottawa |
| Otelfingen | Otelfingen |
| Otelo | Othello |
| Otep | OTEP |
| Othello | Othello |
| Other Voices | The Doors |
| Othmarsingen | Othmarsingen |
| Othniel Charles Marsh | Othniel Charles Marsh |
| Othnielia | Othnielia |
| otimismo | Optimismus |
| otimista | fröhlich |
| otimizar | optimieren |
| Otimização combinatória | Kombinatorische Optimierung |
| Otimização para Sistemas de Busca | Suchmaschinenoptimierung |
| Otimização para Sistemas de Busca SEO | Suchmaschinenoptimierung |
| Otis Redding | Otis Redding |
| Otite | Akute Mittelohrentzündung |
| Otite média aguda | Akute Mittelohrentzündung |
| Otl Aicher | Otl Aicher |
| Otman | Uthman ibn Affan |
| Otniel | Otniel |
| Oto da Baviera | Otto |
| Otocinclus | Ohrgitterwelse |
| Otomis | Otomí |
| otorreia | Otorrhöe |
| otorrinolaringologia | Otorhinolaryngologie |
| Otosclerose | Otosklerose |
| Otoscópio | Otoskopie |
| Otranto | Otranto |
| OTSC | Organisation des Vertrags über kollektive Sicherheit |
| Otsego | Otsego |
| Ottavio Bottecchia | Ottavio Bottecchia |
| Ottawa | Ottawa |
| Ottawa Senators | Ottawa Senators |
| Ottenbach | Ottenbach ZH |
| Ottenhofen | Ottenhofen |
| Ottenhöfen | Ottenhöfen im Schwarzwald |
| Ottensoos | Ottensoos |
| Ottersweier | Ottersweier |
| Otto Braun | Otto Braun |
| Otto de Habsburgo | Otto von Habsburg |
| 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 Jespersen | Otto Jespersen |
| Otto Lilienthal | Otto Lilienthal |
| Otto Ludwig | Otto Ludwig |
| Otto Ludwig Binswanger | Otto Binswanger |
| Otto Nordenskjöld | Otto Nordenskjöld |
| Otto Paul Hermann Diels | Otto Paul Herrmann Diels |
| Otto Preminger | Otto Preminger |
| Otto Skorzeny | Otto Skorzeny |
| Otto Stern | Otto Stern |
| Otto von Bismarck | Otto von Bismarck |
| Otto von Guericke | Otto von Guericke |
| Otto Wallach | Otto Wallach |
| Otto Wilhelm Hermann von Abich | Otto Wilhelm Hermann von Abich |
| Otto Wilhelm von Struve | Otto Wilhelm von Struve |
| Otto Wucherer | Otto Wucherer |
| Ottobrunn | Ottobrunn |
| Ottorino Respighi | Ottorino Respighi |
| Otus asio | Ost-Kreischeule |
| Otzing | Otzing |
| otária | Seebär |
| otário | Dummkopf |
| Otão | Otho |
| Otócion | Löffelhund |
| Otólito | Otolith |
| ou | entweder ... oder |
| ou ... ou | entweder ... oder |
| ou então | anders |
| ou exclusivo | Exklusiv oder |
| ou mais | über |
| ou seja | nämlich |
| Ouabaína | Strophanthin |
| Ouadane | Ouadane |
| Ouagadougou | Ouagadougou |
| OUB Centre | OUB Centre |
| Oubritenga | Oubritenga |
| Oudalan | Oudalan |
| Oudenaarde | Oudenaarde |
| Oueme | Ouémé |
| Ouessant | Ouessant |
| Ouest | Ouest |
| Oulens-sous-Echallens | Oulens-sous-Echallens VD |
| Oulens-sur-Lucens | Oulens-sur-Lucens VD |
| Oulipo | Oulipo |
| Oulu | Oulu |
| Oum el Bouaghi | Oum el Bouaghi |
| Our Daily Bread | Unser täglich Brot |
| Our Love To Admire | Our Love To Admire |
| Ouran High School Host Club | Ouran High School Host Club |
| Ouranossauro | Ouranosaurus |
| Ouray | Ouray |
| Ourea | Ourea |
| ourela | Salband |
| Ourense | Ourense |
| Ourique | Ourique |
| ourives | Goldschmied |
