Hugh O'Reilly (Irish: Aodh Ó Raghallaigh; c.1580–1653) was an Irish prelate of the Roman Catholic Church. He served as Bishop of Kilmore from 1625 to 1628 and Archbishop of Armagh from 1628 to 1653. He was the son of Honora and Mulmore O'Reilly, who was the grandson of the chief of the O'Reilly clan, Fearghal macSeaán, who ruled East Breifne from 1526–1534. Hugh O'Reilly was thus eligible for election to the chieftainship under the system of deirbhfhine. Hugh O'Reilly's genealogy is Aodh son of Maol Mórdha son of Aodh son of Fearghal son of Seaán son of Cathal son of Eóghan na Fésóige. Mulmore O'Reilly had four sons by his wife Honora- Émonn, Hugh O'Reilly (Archbishop of Armagh), Fearghal and Domhnall. He also had an illegitimate son, Cathaoir. In the Plantation of Ulster by grant dated 29