As a designated place in the 2016 Census of Population conducted by Statistics Canada, Cadomin recorded a population of 40 living in 21 of its 92 total private dwellings, a change of from its 2011 population of 36.
In the 2011 Census, Cadomin had a population of 36 living in 22 of its 96 total dwellings, a -35.7% change from its 2006 population of 56.