| Oô | |
| Commune Status: | Commune |
| Arrondissement: | Saint-Gaudens |
| Canton: | Bagnères-de-Luchon |
| Insee: | 31404 |
| Postal Code: | 31110 |
| Mayor: | Jean-Jacques Rives[1] |
| Term: | 2020 - 2026 |
| Coordinates: | 42.7983°N 0.5072°W |
| Elevation M: | 980 |
| Elevation Min M: | 954 |
| Elevation Max M: | 3215 |
| Area Km2: | 32.53 |
Oô (in French pronounced as /ɔ.o/; Occitan (post 1500);: Òu) is a commune in the Haute-Garonne department in the Occitanie region in southwestern France. It borders Spain on its southern side.
Its inhabitants are called Ousiens.
The Lac d'Oô is situated in the commune.