In the 2021 Census of Population conducted by Statistics Canada, Long Harbour-Mount Arlington Heights had a population of 185 living in 97 of its 167 total private dwellings, a change of -26% from its 2016 population of 250. With a land area of 18.33 km2 (7.08 sq mi), it had a population density of 10.1/km2 (26.1/sq mi) in 2021.[2]