The canton of Montfort-l'Amaury is a former canton of France, located in the Yvelines department. It was disbanded following the French canton reorganisation which came into effect in March 2015. It had 40,027 inhabitants and 29 communes:
Auteuil : 864Autouillet : 348Bazoches-sur-Guyonne : 477Béhoust : 374Beynes : 7,200Boissy-sans-Avoir : 519Flexanville : 525Galluis : 1,034Garancières : 2,242Goupillières : 381Grosrouvre : 763Jouars-Pontchartrain : 4,569Marcq : 597Mareil-le-Guyon : 348Méré : 1,675Les Mesnuls : 883Millemont : 206Montfort-l'Amaury : 3,137Neauphle-le-Château : 2 771Neauphle-le-Vieux : 707La Queue-les-Yvelines : 1 844Saint-Germain-de-la-Grange : 1 622Saint-Rémy-l'Honoré : 1 299Saulx-Marchais : 600Thoiry : 969Le Tremblay-sur-Mauldre : 813Vicq : 259Villiers-le-Mahieu : 615Villiers-Saint-Fréderic : 2 386