James McMahon may refer to:
Politics James McMahon (Canadian politician) (1830–1909), Ontario, Canada doctor and politician James Leslie McMahon or Les McMahon (1930–2015), Australian politician James O'Brien McMahon or Brien McMahon (1903–1952), United States senator Jim McMahon (politician) (born 1980), British politician
Others James McMahon (priest) (1817–1901), Irish-born priest James McMahon (astronomer), American amateur astronomer James McMahon (businessman) (1838–1914), Irish-Australian businessman James McMahon (mathematician) (1856–1922), American educator and mathematician James E. McMahon, United States Attorney in South Dakota Jim McMahon (born 1959), American football player James MacMahon (c. 1857–1915), Australian impresario, of MacMahon brothers
See also James Macmahon (1865–1954), Irish businessman