Erieau is an unincorporated community in Ontario, Canada. It is recognized as a designated place by Statistics Canada.
In the 2021 Census of Population conducted by Statistics Canada, Erieau had a population of 363 living in 187 of its 318 total private dwellings, a change of from its 2016 population of 389. With a land area of , it had a population density of in 2021.