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