McGregor Bay is an unincorporated community in Ontario, Canada. It is recognized as a designated place by Statistics Canada.
McGregor Bay is on the LaCloche Peninsula within the Manitoulin District.
In the 2021 Census of Population conducted by Statistics Canada, McGregor Bay had a population of living in of its total private dwellings, a change of from its 2016 population of . With a land area of , it had a population density of in 2021.