George Henry Martin Johnson (Onwanonsyshon) (October 7, 1816 – February 19, 1884) was a member of the Wolf clan and selected as a hereditary chief of the Mohawk of the Six Nations in Canada; he also served as an official interpreter and informal diplomat between the Mohawk and Canadian governments. His home of Chiefswood, built in 1856 on the Grand River, has been designated and preserved as a National Historic Site; it is the only First Nations mansion from the pre-Canadian Confederation era.