L'Île-Dorval is a former municipality in southwestern Quebec, Canada, in Lac Saint-Louis off of the Island of Montreal.

A cottaging spot, it had only two permanent residents, making it the smallest municipality in Canada both in area and population. It was connected to the island of Montreal with a seasonal ferry service.

On January 1, 2002, it merged with the city of Montreal. With the former city of Dorval, it makes up the borough of Dorval/L'Île-Dorval.