| Le Sourn | |
| Native Name: | Ar Sorn |
| Commune Status: | Commune |
| Coordinates: | 48.0436°N -2.9886°W |
| Insee: | 56246 |
| Postal Code: | 56300 |
| Arrondissement: | Pontivy |
| Canton: | Pontivy |
| Mayor: | Jean-Jacques Videlo[1] |
| Term: | 2020 - 2026 |
| Intercommunality: | Pontivy Communauté |
| Elevation Min M: | 46 |
| Elevation Max M: | 184 |
| Area Km2: | 16.05 |
Le Sourn (in French pronounced as /lə suʁn/; Occitan (post 1500);: Ar Sorn) is a commune in the Morbihan department of Brittany in north-western France.[2]
Inhabitants of Le Sourn are called in French Sournais.