Montigny-le-Bretonneux (French pronunciation: [mɔ̃tiɲi lə bʁətɔnø] (listen)) is a commune in the Yvelines department in the Île-de-France region in north-central France. It is located in the south-western suburbs of Paris, 24.5 kilometres (15.2 miles) from the centre of Paris, in the "new town" of Saint-Quentin-en-Yvelines, of which it is the central and most populated commune.