In the
2021 Census of Population conducted by
Statistics Canada, Saint-Eustache had a population of living in of its total private dwellings, a change of from its 2016 population of . With a land area of , it had a population density of in 2021. Population trend: • Population in 2021: 45,276 (2016 to 2021 population change: 2.9%) • Population in 2016: 44,008 (2011 to 2016 population change: -0.3%) • Population in 2011: 44,154 (2006 to 2011 population change: 4.9%) • Population in 2006: 42,062 (2001 to 2006 population change: 4.2%) • Population in 2001: 40,378 • Population in 1996: 39,848 • Population in 1991: 37,278 • Population in 1986: 32,226 • Population in 1981: 29,771 • Population in 1976: 21,248 • Population in 1971: 9,479 • Population in 1966: 7,319 • Population in 1961: 5,463 • Population in 1956: 3,740 • Population in 1951: 2,615 • Population in 1941: 1,564 • Population in 1931: 1,187 • Population in 1921: 1,098 • Population in 1911: 996 • Population in 1901: 1,079 • Population in 1891: 960 • Population in 1881: 814 • Population in 1871: 858 • Population in 1861: 915 • Population in 1851: 784 Mother tongue (as of 2021) : • French as first language: 83.9% • Other as first language: 8.7% • English as first language: 4.2% • English and French as first language: 1.5% == Transport ==