In the 2021 Census of Population conducted by Statistics Canada, Saint-Nazaire-de-Dorchester had a population of 338 living in 149 of its 178 total private dwellings, a change of -6.9% from its 2016 population of 363. With a land area of 51.56 km2 (19.91 sq mi), it had a population density of 6.6/km2 (17.0/sq mi) in 2021.[4]