Agostino Ernesto Castrillo (18 February 1904 – 16 October 1955) was an Italian Roman Catholic professed member of the Order of Friars Minor and the Bishop of San Marco Argentano Bisignano. Castrillo served as a pastor in Foggia during World War II and died of lung cancer not long following his 1953 appointment as a bishop. The cause for sainthood commenced on 14 November 1984 in which he was granted the posthumous title of Servant of God.