Châteauguay is a provincial riding (electoral district) in the Montérégie region of Quebec, Canada, that elects members to the National Assembly of Quebec. It notably includes the city of Châteauguay. It was originally created in 1867 (and an electoral district of that name existed earlier in the Legislative Assembly of the Province of Canada). Its final election was in 1936. It disappeared in the 1939 and its successor electoral district was Châteauguay-Laprairie. However, Châteauguay-Laprairie only existed for one election. Châteauguay was re-created for the 1944 election.