| ornate | très orné |
| Ornate angelshark | Squatina tergocellata |
| Ornate butterflyfish | Poisson-papillon orné |
| Ornate Hawk-eagle | Spizaetus ornatus |
| Ornate Lorikeet | Loriquet orné |
| Ornella Muti | Ornella Muti |
| Ornithischia | Ornithischia |
| Ornithogalum umbellatum | Ornithogale en ombelle |
| ornithological | ornithologique |
| ornithologist | ornithologue |
| ornithology | ornithologie |
| Ornithomimidae | Ornithomimidae |
| Ornithomimosauria | Ornithomimidae |
| Ornithorhynchidae | Ornithorhynchidae |
| Orny | Orny |
| Oro Province | Northern Province |
| Orobanchaceae | Orobanchaceae |
| Orochi | Fatal Fury |
| Orochimaru | Orochimaru |
| Orodruin | Montagne du Destin |
| Orofino | Orofino |
| Orographic lift | Onde orographique |
| orography | orographie |
| Orologio | Orologio |
| Orom | Orom |
| Oromia Region | Oromia |
| Oromo | Galla |
| Oromë | Oromë |
| Oron-la-Ville | Oron-la-Ville |
| Oron-le-Châtel | Oron-le-Châtel |
| Orona | Orona |
| Oronce Finé | Oronce Fine |
| Orontes River | Oronte |
| Oronzio Gabriele Costa | Oronzio Gabriele Costa |
| Oropharyngeal airway | Canule de Guedel |
| Oropos | Oropos |
| Oroqen | Oroqen |
| Orosirian | Orosirien |
| Orosius | Paul Orose |
| Oroville | Oroville |
| Orozko | Orozko |
| orphan | orphelin |
| Orphan drug | Médicament orphelin |
| orphanage | orphelinat |
| Orphans of the Sky | Les Orphelins du ciel |
| Orphans of the Storm | Les Deux Orphelines |
| Orphean Warbler | Fauvette orphée |
| Orpheus | Orphée |
| Orpheus in the Underworld | Orphée aux Enfers |
| Orphism | Orphisme |
| Orpund | Orpund |
| Orquesta Sinfónica de Galicia | Orchestre symphonique de Galice |
| Orr | ORR |
| Orreries | Planetaire |
| Orrin Hatch | Orrin Hatch |
| Orrorin tugenensis | Orrorin tugenensis |
