Darío del Niño Jesús Castrillón Hoyos (4 July 1929 – 18 May 2018) was a Colombian cardinal of the Catholic Church. He was Prefect of the Congregation for the Clergy from 1996 to 2006. He was the president emeritus of the Pontifical Commission "Ecclesia Dei" having served from 2000 until his retirement in 2009. He was elevated to the cardinalate in 1998.