| ostruzionista | obstruktiv |
| Ostrya carpinifolia | Europäische Hopfenbuche |
| Ostróda | Ostróda |
| Ostrów Wielkopolski | Ostrów Wielkopolski |
| Ostsiedlung | Deutsche Ostsiedlung |
| Osumi | Provinz Ōsumi |
| Osun | Osun |
| Osvaldo | Oswald |
| Osvaldo Ardiles | Osvaldo Ardiles |
| Osvaldo Cavandoli | Osvaldo Cavandoli |
| Osvaldo Dorticós Torrado | Osvaldo Dorticós Torrado |
| Oswald Gracias | Oswald Gracias |
| Oswald Mosley | Oswald Mosley |
| Oswald Pohl | Oswald Pohl |
| Oswald Spengler | Oswald Spengler |
| Oswald Theodore Avery | Oswald Avery |
| Oswald West State Park | Oswald West State Park |
| Oswiecim | Auschwitz |
| Oswine di Deira | Oswine |
| Oswiu di Northumbria | Oswiu |
| osé | scharf |
| OT | OT |
| OTA | OTA |
| Otaci | Otaci |
| Otago | Otago |
| Otaku | Otaku |
| otalgia | Ohrenschmerzen |
| Otar Iosseliani | Otar Iosseliani |
| otarda | Trappe |
| otaria | Robbe |
| otaria orsina | Seebär |
| Otariidae | Ohrenrobben |
| Otaru | Otaru |
| Otelfingen | Otelfingen |
| Otello | Othello |
| Otenere | Sich erwerben |
| Otep | OTEP |
| Otfried Preussler | Otfried Preußler |
| Othello | Othello |
| Other Voices | The Doors |
| Othmarsingen | Othmarsingen |
| Othmàn ibn Affàn | Uthman ibn Affan |
| Othniel Charles Marsh | Othniel Charles Marsh |
| Oti | Pendjari |
| Otiorhynchus | Dickmaulrüssler |
| Otira | Otira |
| Otis Elevator Company | Otis Elevator Company |
| Otis Redding | Otis Redding |
| Otis tarda | Großtrappe |
| Otite | Akute Mittelohrentzündung |
| Otite media | Akute Mittelohrentzündung |
| Otmar Freiherr von Verschuer | Otmar Freiherr von Verschuer |
| OTO | Oto |
| Otocyon megalotis | Löffelhund |
| Otolite | Otolith |
| Otone | Otho |
| otorinolaringoiatra | Hals-Nasen-Ohren-Ärztin |
| otorinolaringologia | Otorhinolaryngologie |
| otorrea | Otorrhöe |
| Otowi | Otowi |
| Otočac | Otočac |
| Otranto | Otranto |
| OTRS | Open Ticket Request System |
| ottagonale | achteckig |
| ottagono | Achteck |
| Ottakring | Ottakring |
| Ottanitrocubano | Octanitrocuban |
| ottano | Oktan |
| ottanta | Achtzig |
