In the 2021 Census of Population conducted by Statistics Canada, Isle aux Morts had a population of  living in  of its  total private dwellings, a change of  from its 2016 population of .
According to the 2021 Census of Population conducted by Statistics Canada, Isle aux Morts had a population of  residing in  part of its total private houses, seeing an increase of  from its 2016 resident count.