John McKellar (June 10, 1833 – February 3, 1900) was a businessman and political figure in Ontario, Canada.
He was born in Mosa Township, London District, Upper Canada, the son of Duncan McKellar and Margaret Brodie, both immigrants from Scotland, and was schooled at home.
The family moved to Ontonagon County in 1855 but left Michigan at the start of the American Civil War.
With the aid of his cousin Archibald McKellar, he received a land grant on the Kaministiquia River within the future borders of Fort William.
McKellar served on the council for the municipality of Shuniah which governed the Lakehead townships.