| Lassur | |
| Commune Status: | Commune |
| Arrondissement: | Foix |
| Canton: | Haute-Ariège |
| Insee: | 09159 |
| Postal Code: | 09310 |
| Mayor: | Richard Martinez[1] |
| Term: | 2020 - 2026 |
| Coordinates: | 42.7706°N 1.7378°W |
| Elevation M: | 620 |
| Elevation Min M: | 575 |
| Elevation Max M: | 1946 |
| Area Km2: | 11.99 |
Lassur (pronounced as /fr/; oc|Lhassur) is a commune in the Ariège department in southwestern France.