| organisatrice van revivals | revivalist |
| organisch | organic |
| Organische architectuur | Organic architecture |
| Organische chemie | Organic chemistry |
| Organische Licht Emitterende Diode | Organic light-emitting diode |
| Organische lichtemitterende diode | Organic light-emitting diode |
| Organische synthese | Organic reaction |
| Organische verbinding | Organic compound |
| organiseren | arrange |
| organisme | body |
| organist | organist |
| organiste | organist |
| Organometaalchemie | Organometallic chemistry |
| Organotroof | Organotroph |
| Organum | Organum |
| Orgasmatron | Orgasmatron |
| orgasme | orgasm |
| orgel | organ |
| orgeldraaier | organ-grinder |
| Orgelvogels | Artamidae |
| Orgetorix | Orgetorix |
| orgiastisch | orgiastic |
| orgie | bacchanal |
| Orgyen Trinley Dorje | Ogyen Trinley Dorje |
| Orhan I | Orhan I |
| Orhan Pamuk | Orhan Pamuk |
| Ori | Ori |
| Oriana Fallaci | Oriana Fallaci |
| Oribi | Oribi |
| Orichalcum | Orichalcum |
| Orient Thai airlines | Orient Thai Airlines |
| Oriental | Oriental Region |
| Oriental Pearl Tower | Oriental Pearl Tower |
| Oriente | Oriente |
| Oriented Strand Board | Oriented strand board |
| origami | origami |
| Origenes | Origen |
| Original Design Manufacturer | Original design manufacturer |
| Original Six | Original Six |
| originaliteit | originality |
| origine | origin |
| origineel | original |
| Origlio | Origlio |
| Orihuela CF | Orihuela CF |
| Orinoco | Orinoco |
| Orinoco-appel | Solanum sessiliflorum |
| Orinocodolfijn | Boto |
| Orinocokrokodil | Orinoco Crocodile |
| Orion | Orion |
| Orioniden | Orionids |
| Orionnevel | Orion Nebula |
| Orisha | Orisha |
| Orissa | Orissa |
| Orissaare | Orissaare Parish |
| Oristano | Province of Oristano |
| Oriya | Oriya language |
| Oriënt | Orient |
| Oriënt-Express | Orient Express |
| Oriëntaals gebied | Indomalaya ecozone |
| Oriëntaals-orthodoxe Kerken | Oriental Orthodoxy |
| Oriëntaalse hoornaar | Oriental hornet |
| oriëntalist | orientalist |
