Cormatin is a commune in the Saône-et-Loire department in the region of Bourgogne-Franche-Comté in eastern France. The village, on the riv…Cormatin is a commune in the Saône-et-Loire department in the region of Bourgogne-Franche-Comté in eastern France. The village, on the river Grosne, is home to a castle. The Grosne forms part of the commune's south-western border, then flows northward through the western part of the commune.