| Le Theil-de-Bretagne | |
| Native Name: | (Gallo) |
| Commune Status: | Commune |
| Coordinates: | 47.9203°N -1.4286°W |
| Insee: | 35333 |
| Postal Code: | 35240 |
| Arrondissement: | Fougères-Vitré |
| Canton: | La Guerche-de-Bretagne |
| Mayor: | Benoît Clément[1] |
| Term: | 2020 - 2026 |
| Intercommunality: | Roche-aux-Fées |
| Elevation Min M: | 42 |
| Elevation Max M: | 106 |
| Area Km2: | 24.20 |
Le Theil-de-Bretagne (in French pronounced as /lə tɛj də bʁətaɲ/, literally Le Theil of Brittany; Gallo: Le Teilh,) is a commune in the Ille-et-Vilaine department in Brittany in northwestern France.
Inhabitants of Le Theil-de-Bretagne are called Theillais in French.