| Ottavio Bottecchia | Ottavio Bottecchia |
| Ottawa | Ottawa |
| Ottawa Conventie | Ottawa Treaty |
| Ottawa Lynx | Ottawa Lynx |
| Ottawa Senators | Ottawa Senators |
| Ottendorf-Okrilla | Ottendorf-Okrilla |
| Ottenhofen | Ottenhofen |
| Ottenhöfen im Schwarzwald | Ottenhöfen |
| Ottensoos | Ottensoos |
| Ottenstein | Ottenstein |
| Ottenthal | Ottenthal |
| otter | otter |
| Otterberg | Otterberg |
| Ottercivetkat | Otter Civet |
| Otterfing | Otterfing |
| Otterndorf | Otterndorf |
| Ottersberg | Ottersberg |
| Otterstadt | Otterstadt |
| Ottersweier | Ottersweier |
| Otterthal | Otterthal |
| Otterup | Otterup municipality |
| Otting | Otting |
| Otto | Otto |
| Otto de Rijke | Otto |
| Otto Diels | Otto Diels |
| Otto Dix | Otto Dix |
| Otto Frank | Otto Frank |
| Otto Frans van Oostenrijk | Archduke Otto Franz of Austria |
| Otto Frisch | Otto Robert Frisch |
| Otto Fritz Meyerhof | Otto Fritz Meyerhof |
| Otto Hahn | Otto Hahn |
| Otto Heinrich Warburg | Otto Heinrich Warburg |
| Otto I de Schone | Otto of Greece |
| Otto I van Beieren | Otto of Bavaria |
| Otto I van Gelre | Otto I of Guelders |
| Otto I van Griekenland | Otto of Greece |
| Otto I van Nassau | Otto I of Nassau |
| Otto I van Palts-Mosbach | Otto of Greece |
| Otto II van Lippe | Otto II of Lippe |
| Otto II van Northeim | Otto of Nordheim |
| Otto III van Monferrato | Otto III of Montferrat |
| Otto Jespersen | Otto Jespersen |
| Otto Klemperer | Otto Klemperer |
| Otto Kuusinen | Otto Ville Kuusinen |
| Otto Liebmann | Otto Liebmann |
| Otto Lilienthal | Otto Lilienthal |
| Otto Mann | Otto Mann |
| Otto Mohr | Christian Otto Mohr |
| Otto Müller | Otto Mueller |
| Otto Nicolai | Carl Otto Nicolai |
