| Ottweiler | Ottweiler |
| Otxandio | Otxandio |
| Otzberg | Otzberg |
| Otzing | Otzing |
| OU | OU |
| Ouaddai Empire | Ouaddaï |
| Ouaddai Kingdom | Ouaddaï |
| Ouaddaï Prefecture | Ouaddaï |
| Ouaddaï Region | Ouaddaï |
| Ouagadougou | Ouagadougou |
| Ouagadougou Airport | Aeroporto di Ouagadougou |
| Ouangani | Ouangani |
| Ouargla | Ouargla |
| Ouargla Province | Provincia di Ouargla |
| Ouarzazate | Ouarzazate |
| oubliette | carcere |
| ouch | oh |
| Oud | Oud |
| Oude Kerk | Origini del Cristianesimo |
| Oudenaarde | Oudenaarde |
| Oudomxai Province | Oudomxay |
| Oudomxay Province | Oudomxay |
| Oudtshoorn Local Municipality | Oudtshoorn |
| Ouessant | Ouessant |
| Ouest Department | Ouest Department |
| ought | zero |
| ought to | dovere |
| OUI | OUI |
| Oulainen | Oulainen |
| Oulens-sous-Echallens | Oulens-sous-Echallens |
| Oulens-sur-Lucens | Oulens-sur-Lucens |
| Oulipo | Oulipo |
| Oullins | Oullins |
| Oulton Park | Circuito di Oulton Park |
| Oulton Park International Gold Cup | International Gold Cup |
| Oulu | Oulu |
| Oulu Province | Oulu |
| Oulu railway station | Oulu |
| Oulujoki | Oulujoki |
| Oulujärvi | Oulujärvi |
| Oulun | Oulun |
| Oulunsalo | Oulunsalo |
| ounce | oncia |
| our | il nostro |
| Our Airline | Air Nauru |
| Our Lady of Aparecida | Nostra Signora di Aparecida |
| Our Lady of Fatima | Madonna di Fatima |
| Our Lady of Guadalupe | Nostra Signora di Guadalupe |
| Our Lady of Kazan | Madonna di Kazan |
| Our Lady of Ljeviš | Nostra Signora di Ljeviš |
| Our Lady of Mount Carmel | Beata Vergine Maria del Monte Carmelo |
| Our Lady of Sorrows | Maria Addolorata |
| Our Lady of the Rosary | Madonna del Rosario |
| Our Land | Maamme |
| Our Love to Admire | Our Love to Admire |
| Our River | OUR |
| Our Ukraine | Nostra Ucraina |
| Our Ukraine Bloc | Nostra Ucraina |
| Our Worlds at War | Our Worlds at War |
| Ouran High School Host Club | Host Club - Amore in affitto |
| Ouranosaurus | Ouranosaurus nigeriensis |
