Born on 23 May 1949 in Ohio, Daniel Cardinal DiNardo has a twin sister and two other siblings.
He undertook his high school studies in Pittsburgh and studied for the priesthood there. He was ordained on 16 July 1977 for the diocese of Pittsburgh and later undertook further studies in Rome at the Gregorian and the Augustinianum. He worked for the Congregation for Bishops in Rome from 1984 to 1991 and taught at the Pontifical North American College.
He then returned to Pittsburgh to be a parish priest. Pope John Paul II appointed him Coadjutor Bishop of Sioux City on 19 August 1997. He was consecrated on 7 October 1997 by Bishop Soens, the Bishop of Sioux City. He took over full governance of the diocese on 28 November 1998.
He was then named Coadjutor Bishop of Galveston-Houston on 16 January 2004. He was promoted to the rank of Archbishop when the diocese became an archdiocese on 29 December 2004. He succeed to full governance of the archdiocese on 28 February 2006.
Pope Benedict XVI made him a Cardinal on 24 November 2007.