John O'Malley
John O'Malley may refer to:

John O'Malley (politician) (1878–1940), American politician and businessman in Milwaukee, Wisconsin
John F. O'Malley (1885–c.1950), American architect based in Rhode Island
John J. O'Malley (1915–1970), American architect primarily for the Archdiocese of New York
John W. O'Malley (born 1927), American Jesuit historian of religion

See also
John O'Meally
John Mallee