Lachine (ləshēnˈ) [key], city (1991 pop. 35,266), S Que., Canada, on Montreal island, at the east end of Lake St. Louis just SW of Montreal. Its industries include iron and steel foundries and the manufacture of tires, electrical appliances, and electronics. Lachine was first settled in 1675 and in 1689 was the scene of a battle between the French and the Iroquois. The city is the southwest terminal of the Lachine Canal, connecting Lake St. Louis with the St. Lawrence River at Montreal. Constructed between 1821 and 1825 (later enlarged) to bypass the Lachine Rapids of the St. Lawrence, the canal has been superseded by the St. Lawrence Seaway canals.