The region known locally as the "West Island" covers the entire western third of the island of Montreal. In 2006, eight of the West Island’s thirteen municipalities officially demerged from the “Mega-City” of Montreal. The three Boroughs of Lachine, Ile Bizard/Ste.Geneviève and Pierrefonds/Roxboro, remain part of the Mega-City. The remaining eight autonomous municipalities include Ste.-Anne-de-Bellevue, Senneville, Baie D’Urfé, Beaconsfield, Pointe Claire, Kirkland, Dollard-des-Ormeaux and Dorval.
The name "West Island" is sometimes used to include western "off island" municipalities such as Hudson, St. Lazare, Ile Perrot and Vaudreuil/Dorion. Although it has traditionally drawn English speaking settlers, the West Island has a definite French flavour and has become quite a bilingual and multicultural region.
