Montchauvet () is a commune in the Yvelines department in the ÃÂle-de-France region in north-central France.
A small river named Ru d'Ouville traverses Montchauvet, passing through four other communes to a total length of . The Ru d'Ouville is a tributary of the Vaucouleurs which in turn empties into the Seine.
A British bomber was shot down in the area of Montchauvet on 8 June 1944. The six men of its crew rest in the local graveyard.