| okshoofd | hogshead |
| oktober | October |
| Oktoberfest | Oktoberfest |
| Oktoberrevolutie | October Revolution |
| Oktobristenpartij | Octobrist |
| oké | all right |
| Ol Doinyo Lengai | Ol Doinyo Lengai |
| Olaberria | Olaberria |
| Olaf I | Olaf I |
| Olaf I van Denemarken | Olaf I of Denmark |
| Olaf I van Noorwegen | Olaf I of Norway |
| Olaf II van Noorwegen | Olaf II of Norway |
| Olaf III van Noorwegen | Olaf III of Norway |
| Olaf IV van Noorwegen | Olav IV of Norway |
| Olaf Magnusson | Olaf Magnusson of Norway |
| Olaf Olafsson | Ólafur Jóhann Ólafsson |
| Olaf V van Noorwegen | Olav V of Norway |
| Olancho | Olancho |
| Olang | Olang |
| Olanzapine | Olanzapine |
| OLAP | Online analytical processing |
| Olaus Magnus | Olaus Magnus |
| Olavarría | Olavarría Partido |
| Olavinlinna | Olavinlinna |
| Olbendorf | Olbendorf |
| Olbernhau | Olbernhau |
| Olbersleben | Olbersleben |
| Olbia | Olbia |
| Olbia-Tempio | Province of Olbia-Tempio |
| Olching | Olching |
| Olchon | Olkhon |
| Old Acquaintance | Old Acquaintance |
| Old Faithful | Old Faithful Geyser |
| Old King Cole | Old King Cole |
| Old school hiphop | Old school hip hop |
| Old Shatterhand | Old Shatterhand |
| Old Trafford | Old Trafford |
| Old Vic | Old Vic |
| Oldboy | Oldboy |
| Oldenburg | Oldenburg |
| Oldenburg in Holstein | Oldenburg |
| Oldenswort | Oldenswort |
| Oldfield Thomas | Oldfield Thomas |
| Oldham | Oldham |
| Oldham County | Oldham County |
| Oldowan | Olduwan |
| Oldrik | Ulric |
| Oldsmobile | Oldsmobile |
| oldtimer | old-timer |
| Olduvaikloof | Olduvai Gorge |
| Oldřich II van Bohemen | Oldrich of Bohemia |
| Oldřich van Bohemen | Oldrich of Bohemia |
| Ole Bull | Ole Bull |
| Ole Einar Bjørndalen | Ole Einar Bjørndalen |
| Ole Gunnar Solskjær | Ole Gunnar Solskjær |
| Ole Madsen | Ole Madsen |
| Ole Rømer | Ole Rømer |
| oleander | oleander |
| Oleanderpijlstaart | Daphnis nerii |
| Olecko | Olecko |
| Oleg Antonov | Oleg Antonov |
| Oleg Bozjev | Oleg Bozhev |
| Oleg Cassini | Oleg Cassini |
| Oleg Deripaska | Oleg Deripaska |
| Oleg Konstantinovitsj van Rusland | Prince Oleg Konstantinovich of Russia |
| Oleg Popov | Oleg Popov |
| Oleg Romanisjin | Oleg Romanishin |
| Oleg Salenko | Oleg Salenko |
| Oleg van Kiev | Oleg of Novgorod |
| Oleg Vladimirovich Losev | Oleg Losev |
| Oleguer Presas | Oleguer Presas |
| Oleh Blochin | Oleg Blokhin |
| Oleh Lisohor | Oleg Lisogor |
| Oleh Loezjny | Oleh Luzhny |
| Oleksandr Aliejev | Olexandr Aliyev |
| Oleksandr Beljavsky | Alexander Beliavsky |
| Oleksandr Moroz | Oleksandr Moroz |
| Oleksandr Ponomarjov | Oleksandr Ponomaryov |
| Oleksandr Sjovkovskyj | Oleksandr Shovkovskiy |
| Olena Hroesjyna | Elena Grushina |
| Olenekien | Olenekian |
| Oleni | Oleni |
| Olenjok | Olenyok River |
| oleografie | oleograph |
| Olestra | Olestra |
| Oleszyce | Oleszyce |
| Oleum | Oleum |
| Oleśnica | Oleśnica |
| Olešnice | Olešnice |
| olfactorisch | olfactory |
| Olfen | Olfen |
| Olga Aleksandrovna van Rusland | Grand Duchess Olga Alexandrovna of Russia |
| Olga Bondarenko | Olga Bondarenko |
| Olga Jegorova | Olga Yegorova |
| Olga Kaniskina | Olga Kaniskina |
| Olga Kern | Olga Kern |
| Olga Knipper | Olga Knipper |
| Olga Koezenkova | Olga Kuzenkova |
| Olga Konstantinova van Rusland | Olga Konstantinovna of Russia |
| Olga Markova | Olga Markova |
| Olga Neuwirth | Olga Neuwirth |
| Olga Nikolajevna van Rusland | Grand Duchess Olga Nikolaevna of Russia |
| Olga Poetsjkova | Olga Poutchkova |
| Olga Pyljova | Olga Pyleva |
| Olga Rjabinkina | Olga Ryabinkina |
| Olga Roebtsova | Olga Rubtsova |
| Olga Savtsjoek | Olga Savchuk |
| Olga Valerianovna Karnovitsj | Olga Valerianovna Paley |
| Olga van Griekenland en Denemarken | Princess Olga of Greece and Denmark |
| Olga van Kiev | Olga of Kiev |
| Olga Zajtseva | Olga Zaitseva |
| Olgiate Comasco | Olgiate Comasco |
| Olhão | Olhão |
| Olib | Olib |
| olibanum | frankincense |
| olie | oil |
