The diocese of Auxerre is a former French Roman Catholic diocese. Its historical episcopal see was in the city of Auxerre in Burgundy, now part of eastern France. Currently the non-metropolitan Archbishop of Sens, ordinary of the diocese of Sens and Auxerre, resides in Auxerre.

Auxerre is the capital (prefecture) of the Yonne department and the fourth-largest city in the Burgundy historical region southeast of Paris. Auxerre's population today is about 35,000; the urban area comprises roughly 113,000 inhabitants. Residents of Auxerre are referred to as Auxerrois.