Harry Baker Humphrey (4 August, 1873–1955) was an American botanist.[1]: 120–123 He was a pathologist with the USDA, specializing on research on breeding resistance to grain smut, and president of the American Phytopathological Society.[1]: 122 His posthumously published book Makers of North American Botany (1961) contains 121 brief biographies of outstanding botanists active in North America.[2]