John Costello

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