Châteauguay—Saint-Constant was a federal electoral district in Quebec, Canada, that was represented in the House of Commons of Canada from 2004 to 2015. Its population in 2006 was 107,165. Châteauguay—Saint-Constant was created in 2003 from Châteauguay riding, with the exception of a portion of Châteauguay that was transferred in Beauharnois—Salaberry and Saint-Jean ridings.