Saint-Eustache (French pronunciation: [sɛ̃t‿østaʃ] ^ⓘ) is an off-island suburb of Montreal, in western Quebec, Canada, west of Montreal on the north shore of the Rivière des Mille Îles. It is located 35 km (22 mi) northwest of Montreal.

The city was founded in 1770 and was incorporated in 1835.

The Battle of Saint-Eustache in the Lower Canada Rebellion was fought there on December 14, 1837. The rebels were defeated, and the town was burnt. The church was fully rebuilt after the burning except for the front facade.

Saint-Eustache was home to the Autodrome Saint-Eustache from 1965 to 2019.

In the 2021 Census of Population conducted by Statistics Canada, Saint-Eustache had a population of 45,276 living in 18,958 of its 19,396 total private dwellings, a change of 2.9% from its 2016 population of 44,008. With a land area of 70.51 km² (27.22 sq mi), it had a population density of 642.1/km² (1,663.1/sq mi) in 2021.

Population trend:

Mother tongue (as of 2021) :

There used to be a train station in Saint-Eustache from 1882 to 1940. It operated service to and from Sainte-Thérèse.