In the 2021 Census of Population conducted by Statistics Canada, Saint-Arsène had a population of 1,245 living in 468 of its 479 total private dwellings, a change of 1.2% from its 2016 population of 1,230. With a land area of 70.81 km2 (27.34 sq mi), it had a population density of 17.6/km2 (45.5/sq mi) in 2021.[4]