| Otto II | Otto III | Otto III (Bavaria) |
| Otto J. Schaden | Otto Klemperer | Otto Kuntze |
| Otto Leberecht Lesser | Otto Lesser | Otto Lilienthal |
| Otto Loewi | Otto Ludwig | Otto Meyerhof |
| Otto Nicolai | Otto Paul Hermann Diels | Otto Piringer |
| Otto Preminger | Otto R. Frisch | Otto Rank |
| Otto Redlich | Otto Rehhagel | Otto Robert Frisch |
| Otto Roettig | Otto Roth | Otto Schöpp |
| Otto Schmidt | Otto Scrinzi | Otto Skorzeny |
| Otto Stammer | Otto Stern | Otto Stolz |
| Otto Tellmann | Otto Tolnai | Otto von Below |
| Otto von Bismarck | Otto von Bismark | Otto von Guericke |
| Otto von Habsburg | Otto von Münchhausen | Otto von Munchhausen |
| Otto Wagner | Otto Wallach | Otto Wöhler |
| Otto Weber | Otto Weininger | Otto Wernicke |
| Otto Wilhelm Fischer | Otto Wilhelm Hermann von Abich | Otto Winzer |
| Otto Zardetti | Otto, Indiana | Otto, Prinț Moștenitor al Austriei |
| Otto-Ernest Weber | Otto-Guillaume de Burgundia | Otto-Henric de Burgundia |
| Otto/Novecento | Ottobeuren | Ottobiano |
| Ottobrunn | Ottoi Călin | Ottokar al II-lea al Boemiei |
| Ottokar al II-lea de Stiria | Ottokar al III-lea al Stiriei | Ottokar al III-lea de Stiria |
| Ottokar al IV-lea de Stiria | Ottokar Czernin | Ottokar I al Boemiei |
| Ottokar I de Stiria | Ottola Nesmith | Ottoman Railway Company |
| Ottoman-Wallachian wars | Ottomar Anschütz | Ottomar Rodolphe Vlad Dracula Prince Kretzulesco |
| Otton Sachelarie | Ottone (Italia) | Ottone, Emilia-Romagna |
| Ottorino Respighi | Ottosdal | Ottrau |
| Ottrott | Ottstedt a. Berge | Ottweiler |
| Ottwiller | Otumfuo Nana Osei Tutu al II-lea | Otus scops |
| OTV | Otv | Otveşti |
| Otveşti, Timiş | Otvești | Otvești, Timiș |
| Otwock | Otzberg | Otzi |
| Otzing | Otzingen | Otzweiler |
| Ou | Ou în ceai negru | Ou încondeiat |
| Ou centenar | Ou de o mie de ani | Ou de o sută de ani |
| Ou de Paşti | Ou de Paști | Ou marmorat |
| Ou murat | Ou negru | Ou pestriţ |
| Ou pestriț | OU Press | Ouachita County |
| Ouachita County, Arkansas | Ouachita Parish | Ouachita Parish, Louisiana |
| Ouacif | Ouacifs | Ouad Emour |
| Ouad Naga | Ouadane | Ouadda |
| Ouadhia | Ouadhia District | Ouadjana |
| Ouagadougou | Ouagne | Ouaguenoun |
| Ouahigouya | Ouainville | Ouaka |
| Oualata | Ouallam | Ouamri |
| Ouanaminthe | Ouango | Ouangolodougou, Coasta de Fildeş |
| Ouangolodougou, Coasta de Fildeș | Ouani | Ouaninou |
| Ouanne | Ouanne (Yonne) | Ouanougha |
| Ouara | Ouaragahio | Ouardanine |
| Ouargaye | Ouargla | Ouarizane |
| Ouarville | Ouarzazate | Ouéllah |
| Ouéoulo | Ouésso | Ouă |
| Ouă verzi cu șuncă (serial TV) | Ouăle lui Tarzan | Ouăle roşii |
| Ouăle roșii | Oubangui | Ouchamps |
| Ouches | Oucques | Oud-Beijerland |
| Oud-Heverlee | Oud-Heverlee Leuven | Oud-Turnhout |
| Oudalle | Oudan | Oude IJsselstreek |
| Oude Maas | Oudemans (autor) | Oudemans (biolog) |
| Oudemansiella mucida | Oudenaarde | Oudenburg |
| Ouder-Amstel | Oudergem | Ouderkerk |
| Oudeuil | Oudewater | Oudey Jrid |
| Oudezeele | Oudincourt | Oudjana |
| Oudon | Oudry | Oudry (Saône-et-Loire) |
| Oudtshoorn | Oued Alleug | Oued Athmania |
| Oued Berkeche | Oued Chaaba | Oued Chair |
| Oued Cheham | Oued Chorfa | Oued Djemaa |
| Oued Djer | Oued El Abtal | Oued El Alenda |
| Oued El Alleug | Oued El Aneb | Oued El Barad |
| Oued El Berdi | Oued El Djemaa | Oued El Kheïr |
| Oued El Kheir | Oued El Ma | Oued Endja |
| Oued Essalem | Oued Fodda | Oued Fragha |
| Oued Ghir | Oued Gousine | Oued Goussine |
| Oued Harbil | Oued Keberit | Oued Koriche |
| Oued Lakhdar | Oued lakhdar | Oued Lilli |
| Oued M'Zi | Oued Morra | Oued Nini |
| Oued Rhiou | Oued Sabah | Oued Sebaa |
| Oued Sefioun | Oued Seguen | Oued Sly |
| Oued Smar | Oued Taga | Oued Taourira |
| Oued Taria | Oued Tlélat | Oued Tlelat |
| Oued Zehour | Oued Zenati | Oued Zitoun |
| Oueilloux | Ouellé | Ouenza |
| Ouerre | Ouessant | Ouesso |
| Ouest Side | Ouest-France | Ouezzane |
| Ouffet | Ouffières | Ouges |
| Ougny | Ouham | Ouham-Pendé |
| Ouham-Pende | OuiBaDa | Ouidah |
| Ouides | Ouija | Ouillen |
| Ouillon | Ouilly-du-Houley | Ouilly-le-Tesson |
| Ouilly-le-Vicomte | Ouistreham | Oujda |
| Oul Arşiţei | Oul Arșiței | Oul şi sfera |
| Oul de cristal | Oul de cuc | Oul și sfera |
| Oul gigantic din Suceava | Oul lui Columb | Oul sau găina |
| Oul tradițional de Paște din Suceava | Oul uriaş din Suceava | Oul uriaș din Suceava |
| Oulainen | Oulches | Oulches-la-Vallée-Foulon |
| Oulchy-la-Ville | Oulchy-le-Château | Ould Biram |
| Ould M'Bonny | Ould Yengé | Ouldja Boulballout |
| Ouled | Ouled Aïssa | Ouled Aïssa (Adrar) |
| Ouled Aïssa (Boumerdès) | Ouled Abbes | Ouled Addi Guebala |
| Ouled Addouane | Ouled Ahmed Tammi | Ouled Ahmed Timmi |
| Ouled Aiche | Ouled Aissa, Adrar | Ouled Aissa, Boumerdès |
| Ouled Ammar | Ouled Antar | Ouled Aouf |
