The "arrondissement" of Châtellerault is in northern Vienne and is bordered to the northwest by the Maine-et-Loire department, to the north and east by the Indre-et-Loire department, to the southeast by the Indre department (a small part) and the "arrondissement" of Montmorillon, to the south by the "arrondissement" of Poitiers and to the west by the Deux-Sèvres department.