| Mailly-le-Château | |
| Commune Status: | Commune |
| Image Coat Of Arms: | Blason Mailly-le-Château 89.svg |
| Coordinates: | 47.5969°N 3.6364°W |
| Insee: | 89238 |
| Postal Code: | 89660 |
| Arrondissement: | Auxerre |
| Canton: | Joux-la-Ville |
| Mayor: | Jean-Michel Godefroy[1] |
| Term: | 2020 - 2026 |
| Elevation Min M: | 117 |
| Elevation Max M: | 254 |
| Area Km2: | 37.28 |
Mailly-le-Château (in French pronounced as /maji l(ə) ʃɑto/) is a commune in the Yonne department in Bourgogne-Franche-Comté in north-central France.The lower village is on the left bank of the river Yonne, adjacent to the Canal du Nivernais. The upper village is noted for its 14th-century fortified castle and the 13th-century church of St Adrian.