In the
2021 Census of Population conducted by
Statistics Canada, Blainville 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. Over 8% of residents are under 15, whereas 67% are between 15 and 64 and 15% are over 65. In 2021, 86.5% of Blainville residents were white/European, 12.3% were visible minorities and 1.2% were Indigenous. The largest visible minority groups were
Arab (3.6%),
Black (3.3%),
Latin American (1.7%),
Southeast Asian (0.9%), and
Chinese (0.9%). 66.9% of residents were
Christian, down from 87.1% in 2011. 57.3% were
Catholic, 6.3% were Christian n.o.s, 0.8% were
Protestant and 2.5% belonged to other Christian denominations and Christian-related traditions. Of non-Catholic denominations, the largest is
Christian Orthodox at 1.9%. 28.0% of residents were non-religious or secular, up from 11.6% in 2011. 5.1% belonged to other religions, up from 1.3% in 2011. The largest non-Christian religions were
Islam (4.2%) and
Buddhism (0.4%). The 2021 census found that 82.2% of residents spoke
French as a
mother tongue. Although 60.0% of residents reported knowledge of both English and French, English was the mother tongue of only 4.1% of respondents. The next most frequent native languages were
Arabic (2.3%),
Spanish (1.7%), and
Portuguese (1.0%). ==Economy==