John A. Costello, Irish lawyer and politician, 3rd Taoiseach of Ireland (b. 1891)

John Aloysius Costello (20 June 1891 – 5 January 1976) was an Irish Fine Gael politician who served as Taoiseach from 1948 to 1951 and from 1954 to 1957, Leader of the Opposition from 1951 to 1954 and from 1957 to 1959, and Attorney General of Ireland from 1926 to 1932. He served as a Teachta Dála (TD) from 1933 to 1943 and from 1944 to 1969.