Diego Guzmán de Haros (1566 – 21 January 1631) was a cardinal of the Roman Catholic Church from 1629 to 1631.
[2] On 30 June 1620 Pope Paul V named him Commissary Apostolic of the Bull of the Crusade he issued that year.
[1] Pope Urban VIII created him a cardinal in pectore in the consistory held on 19 November 1629.
[2] In early 1631, he traveled to the Kingdom of Hungary to accompany his former pupil Maria Anna of Spain to her wedding with Ferdinand III, Holy Roman Emperor.
[2] On his way home, he was to travel to Rome to receive the galero from the pope, but he died before that could happen, in Ancona, on 21 January 1631.