| Montoulieu | |
| Commune Status: | Commune |
| Arrondissement: | Foix |
| Canton: | Sabarthès |
| Insee: | 09210 |
| Postal Code: | 09000 |
| Mayor: | Françoise Fernandez[1] |
| Term: | 2022 - 2026 |
| Intercommunality: | CA Pays Foix-Varilhes |
| Coordinates: | 42.9089°N 1.6292°W |
| Elevation M: | 400 |
| Elevation Min M: | 428 |
| Elevation Max M: | 1488 |
| Area Km2: | 14.12 |
Montoulieu (in French pronounced as /mɔ̃tuljø/; Occitan (post 1500);: Montoliu) is a commune in the Ariège department in southwestern France.