| Okhi Day | Ochi-dag |
| Okhotsk | Ochotsk |
| Okhranka | Ochrana |
| Okhta Center | Gazprom City |
| Oki Islands | Oki-eilanden |
| Okinawa | Okinawa |
| Okinawa Island | Okinawa |
| Okinawa Prefecture | Okinawa |
| Oklahoma | Oklahoma |
| Oklahoma - Oklahoma City | Staten van de Verenigde Staten |
| Oklahoma City | Oklahoma City |
| Oklahoma City bombing | Bomaanslag in Oklahoma City |
| Oklo | Oklo |
| Okocim Brewery | Okocim |
| Okolnichy | Okolnitsji |
| Okondo | Okondo |
| Okonek | Okonek |
| okra | okra |
| Okroshka | Okrosjka |
| Okrug | Okroeg |
| Oksana Akinshina | Oksana Akinsjina |
| Oksana Domnina | Oksana Domnina |
| Oktoberfest | Oktoberfest |
| Oktyabrsky | Oktjabrski |
| Okulovka | Okoelovka |
| Ol Doinyo Lengai | Ol Doinyo Lengai |
| Olaberria | Olaberria |
| Olaf I | Olaf I |
| Olaf I of Denmark | Olaf I van Denemarken |
| Olaf I of Norway | Olaf I van Noorwegen |
| Olaf II of Norway | Olaf II van Noorwegen |
| Olaf III of Norway | Olaf III van Noorwegen |
| Olaf Magnusson of Norway | Olaf Magnusson |
| Olancho | Olancho |
| Olang | Olang |
| Olanzapine | Olanzapine |
| OLAP cube | Cube |
| Olaus Magnus | Olaus Magnus |
| Olav | Olof II van Zweden |
| Olav IV of Norway | Olaf IV van Noorwegen |
| Olav V of Norway | Olaf V van Noorwegen |
| Olavarría Partido | Olavarría |
| Olavinlinna | Olavinlinna |
| Olbendorf | Olbendorf |
| Olbernhau | Olbernhau |
| Olbersleben | Olbersleben |
| Olbia | Olbia |
| Olching | Olching |
| old | oud |
| Old Acquaintance | Old Acquaintance |
| old age | ouderdom |
| Old Believers | Oudgelovigen |
| Old Catholic Church | Oud-katholieke Kerk |
| Old Catholic Church of Austria | Oud-katholieke Kerk |
| Old Catholic Mission in France | Oud-katholieke Kerk |
| Old Church Slavonic | Oudkerkslavisch |
| Old City | Oude Stad |
| Old City of Jerusalem | Oude Stad |
| Old Dominion | Virginia |
| Old Dutch | Oudnederlands |
| Old East Slavic | Oudrussisch |
| Old English | Oudengels |
| Old English language | Oudengels |
| Old European Script | Vinča-cultuur |
| Old Faithful Geyser | Old Faithful |
| Old Firm | The Old Firm |
