Lac-Saint-Louis (French pronunciation: [laksɛ̃lwi]) is a federal electoral district in Quebec, Canada, which has been represented in the House of Commons since 1997.

Since 2004, its Member of Parliament (MP) has been Francis Scarpaleggia of the Liberal Party.

The district includes the cities of Beaconsfield, and Pointe-Claire; the towns of Baie-d'Urfé, Kirkland and Sainte-Anne-de-Bellevue; the municipality of Senneville; and the western part of the borough of Pierrefonds-Roxboro of the city of Montreal.

The electoral district was created in 1996 from Lachine—Lac-Saint-Louis and Vaudreuil ridings.

This riding was largely untouched by the 2012 electoral redistribution, gaining a small territory from Notre-Dame-de-Grâce—Lachine.