In the 2021 Census of Population conducted by Statistics Canada, Saints-Martyrs-Canadiens had a population of 277 living in 148 of its 269 total private dwellings, a change of 9.1% from its 2016 population of 254. With a land area of 111.4 km2 (43.0 sq mi), it had a population density of 2.5/km2 (6.4/sq mi) in 2021.[4]