William Howard Taft III (August 7, 1915 — February 23, 1991) was a grandson of President William Howard Taft and First Lady Helen Louise "Nellie" Taft who served as U.S. ambassador to Ireland from 1953 to 1957. He was the eldest of four sons born to Robert Alphonso Taft and Martha Wheaton Bowers. His task as ambassador was made easier by the fact that John A. Costello, Taoiseach 1954-57 was a personal friend; Taft described Costello as "pleasant and unassuming" whereas he had found Éamon de Valera "formal and aloof". (His predecessor George A. Garrett, had also found Costello more sympathetic than De Valera). Taft played a considerable part in organising Costello's successful State visit to the United States in March 1956. Taft was also a member of the Metropolitan Club of Washington D.C. until at least the mid-1980s, perhaps later. Taft was the father of William Howard Taft IV.