In the 2021 Census of Population conducted by Statistics Canada, Saint-Philémon had a population of 680 living in 364 of its 533 total private dwellings, a change of -4.8% from its 2016 population of 714. With a land area of 146.51 km2 (56.57 sq mi), it had a population density of 4.6/km2 (12.0/sq mi) in 2021.[4]