Sainte-Marie-du-Mont is a commune in the Manche department and in the region of Normandy in north-western France. The commune has 712 …Sainte-Marie-du-Mont is a commune in the Manche department and in the region of Normandy in north-western France. The commune has 712 inhabitants. Saint-Marie-du-Mont is located in the southeast of the Cotentin Peninsula, just north of the town of Carentan, and west of the Baie des Veys, the outlet of the Douve and the Vire.