Harold Johnston may refer to:
Harold Johnston (footballer) (1895–1978), Australian rules footballer Harold Whetstone Johnston (1859–1912), American historian known for his writings on ancient Rome Harold I. Johnston (1892–1949), American soldier and Medal of Honor recipient Harold S. Johnston (1920–2012), American atmospheric chemist and National Medal of Science laureate
See also Harry Johnston (disambiguation) Harold Johnson (disambiguation) Harold Johnstone, English footballer