Saint-Jean-sur-Richelieu (French pronunciation: [sɛ̃ ʒɑ̃ syʁ ʁiʃ(ə)ljø]) is a city in eastern Montérégie in the Canadian province of Quebec, about 40 kilometres (25 mi) southeast of Montreal, located roughly halfway between Montreal and the Canada–United States border with the state of Vermont.

It is situated on both the west and east banks of the Richelieu River at the northernmost navigable point of Lake Champlain.

Known to early English settlers as St. Johns, it provided an important communication link during the French and Indian Wars.

The city is the seat of Le Haut-Richelieu regional county municipality and of the judicial district of Iberville.

[9] The amalgamated municipalities (with 2001 population) were: Despite the fact that nearby Montreal is very racially diverse, in 2021 Saint-Jean-sur-Richelieu had a very large majority of white residents (~94.4%).

[15] Newer retail developments include Faubourg Saint-Jean, home to restaurants, services, stores, and a soon-to-open movie theatre.

It hosts an Area Support Unit (ASU) of the Canadian Forces, which functions as a primary recruit and officer training establishment.

The Ville de Saint-Jean-sur-Richelieu public transit system provides commuter and local bus services.

The former Saint-Jean-d'Iberville railway station, which until 1966 served the Ambassador to Boston and New York City and the Washingtonian to Washington, D.C., is now a preserved building.