| Saint-Thonan | |
| Native Name: | Sant-Tonan |
| Commune Status: | Commune |
| Coordinates: | 48.4797°N -4.3344°W |
| Elevation Min M: | 34 |
| Elevation Max M: | 116 |
| Insee: | 29268 |
| Postal Code: | 29800 |
| Arrondissement: | Brest |
| Canton: | Landerneau |
| Mayor: | Marc Jézéquel[1] |
| Term: | 2020 - 2026 |
| Intercommunality: | CA Pays de Landerneau-Daoulas |
| Area Km2: | 11.29 |
Saint-Thonan (in French pronounced as /sɛ̃ tɔnɑ̃/; Breton: Sant-Tonan) is a commune in the Finistère department of Brittany in north-western France.
Inhabitants of Saint-Thonan are called in French Saint-Thonanais.