| Grandchamp-des-Fontaines | |
| Native Name: | (Gallo) |
| Commune Status: | Commune |
| Image Coat Of Arms: | Blason ville fr Grandchamp-des-Fontaines (Loire-Atlantique).svg |
| Arrondissement: | Châteaubriant-Ancenis |
| Canton: | La Chapelle-sur-Erdre |
| Insee: | 44066 |
| Postal Code: | 44119 |
| Mayor: | François Ouvrard[1] |
| Term: | 2020 - 2026 |
| Intercommunality: | Erdre et Gesvres |
| Coordinates: | 47.3658°N -1.6039°W |
| Elevation Min M: | 8 |
| Elevation Max M: | 70 |
| Area Km2: | 33.87 |
Grandchamp-des-Fontaines (in French pronounced as /ɡʁɑ̃ʃɑ̃ de fɔ̃tɛn/; before 2023: Grandchamps-des-Fontaines; Gallo: Graunchaun, Breton: Gregamp-ar-Feunteunioù) is a commune in the Loire-Atlantique department in western France.