John Costello may refer to:
John Costello (baseball) (born 1960), American baseball pitcher John Costello (English footballer) (1890–1915), English footballer John Costello (historian) (1943–1995), British military historian John A. Costello (1891–1976), Taoiseach of Ireland John M. Costello (1903–1976), U.S. Representative from California John Costello (Medal of Honor) (1850–?), U.S. Navy sailor and Medal of Honor recipient John Costello (pastoralist) (1838–1923), Australian pastoralist John W. Costello (born 1927), American attorney and politician in Massachusetts John Costello (Gaelic footballer), Gaelic football player from County Laois John P. Costello (1947–2010), U.S. Army general See also John Costelloe (politician) (c. 1900–?), Irish politician, member of Seanad Éireann from 1963 to 1965 John Costelloe (actor) (1961–2008), American actor