| Bain-de-Bretagne | |
| Native Name: | (Gallo) |
| Commune Status: | Commune |
| Image Coat Of Arms: | Blason ville fr Bain-de-Bretagne (Ille-et-Vilaine).svg |
| Coordinates: | 47.8431°N -1.6806°W |
| Insee: | 35012 |
| Postal Code: | 35470 |
| Arrondissement: | Redon |
| Canton: | Bain-de-Bretagne |
| Mayor: | Dominique Bodin[1] |
| Term: | 2020 - 2026 |
| Intercommunality: | Bretagne Porte de Loire |
| Elevation Min M: | 17 |
| Elevation Max M: | 114 |
| Area Km2: | 64.77 |
Bain-de-Bretagne (Gallo: Bóen) is a commune in the Ille-et-Vilaine department in Brittany in northwestern France.
The river Semnon forms part of the commune's northern boundary.
Inhabitants of Bain-de-Bretagne are called Bainais in French.