For other persons named John Costello, see John Costello. John Aloysius Costello (Irish: Sen Alabhaois Mac Coisdealbha; 20 June 1891 5 January 1976), ...
John Costello may refer to: John Costello (baseball), MLB pitcher; John A. Costello, former Taoiseach of Ireland; John M. Costello (19031976), ...