| Castillon-de-Larboust | |
| Commune Status: | Commune |
| Arrondissement: | Saint-Gaudens |
| Canton: | Bagnères-de-Luchon |
| Insee: | 31123 |
| Postal Code: | 31110 |
| Mayor: | Philippe Crampe[1] |
| Term: | 2020 - 2026 |
| Coordinates: | 42.8069°N 0.5347°W |
| Elevation M: | 1000 |
| Elevation Min M: | 877 |
| Elevation Max M: | 3110 |
| Area Km2: | 20.67 |
Castillon-de-Larboust is a commune in the Haute-Garonne department in southwestern France.