O'Reilly, Hugh (Aodh Ó Raghallaigh) (c.1581–1653), catholic archbishop of Armagh, was born ‘in the province of Ulster of one of the chief families of Ireland’ (HMC, Franciscan MSS, 96–7), son of Maolmórdha mac Aodha O'Reilly and his wife Mór. Hugh was descended from the O'Reilly chieftains. His great-grandfather, Fergal O'Reilly, ‘lord of Hy-Briuin and Conmaicne . . . a generous, potent, upright, and truly hospitable man’ (AFM, 1536), died in 1536. Hugh's family lived until 1611 in the parish of Ballintemple, Co. Cavan, when their lands were confiscated in the plantation of Ulster. O'Reilly's family received 300 acres of poorer land in the barony of Tullyhaw, Co. Cavan, in compensation.
He was educated by the Franciscans, whom his ancestor Sean O'Reilly (qv) (d. 1510) had brought to Cavan (AFM, 1510). Although his father wanted him to be a soldier, O'Reilly was ordained priest in Ireland before continuing his education on the continent. He studied philosophy at Rouen and theology at Paris before travelling to Rome. Throughout his life he retained a good standard of Irish and Latin learning, although his English was poor. In 1626 he was described as being ‘well versed in both civil and canon law and theology’. Appointed bishop of Kilmore, his native diocese, in 1625, he returned to Ireland and was consecrated in July 1626 by Archbishop Thomas Fleming (qv) in St Peter's church, Drogheda. In April 1628 Anna Isabella, wife of Archduke Albert of Austria, recommended him as one of three possible candidates for the vacant see of Armagh, a recommendation seconded in June by the papal nuncio at Brussels. He was appointed archbishop of Armagh on 11 August 1628. He lived at Lough Oughter, Co. Cavan.
Throughout 1629–31 O'Reilly corresponded with Luke Wadding (qv) and Pope Urban VIII in Rome about various ecclesiastical matters, including a proposal in 1631 that St Patrick's Purgatory on Lough Derg in Co. Donegal be given over to the Observant Franciscans. (HMC, Franciscan MSS, 37). As archbishop, O'Reilly began to reorganise his diocese, ordering small shelters to be built to end the practice of mass being celebrated in the open, and working to eliminate divorce in the areas under his authority. He held a synod at Ardagh in 1632 and convened a second synod in 1637. The same year he had a dispute with Bonaventure Magennis, bishop of Down and Connor (1630–40), which the archbishop referred to Rome. Around this time he was detained by the English authorities and imprisoned for six months. This may have been related to his dispute with Magennis, though O'Reilly later blamed a Donal Casey for his arrest.
O'Reilly opposed secular Gaelic leaders having any major influence in his province. He also opposed the appointment of clerics of Old English descent to bishoprics in Gaelic areas. He was not involved in planning the 1641 rising in Ulster, but soon acquired a prominent role amongst the catholic leadership as the rebellion gathered momentum. In February 1642 he wrote to Luke Wadding seeking financial aid from the papal curia and on 22 March 1642 held a provincial synod at Kells which legitimised the rebellion as a war in defence of the catholic religion (Ó hAnnracháin, Catholic reformation in Ireland, 275–6). This synod of the Armagh province also drew up plans for the recovery of churches from the protestant interest and called for the catholics of Ireland to establish a civil administration. O'Reilly played a prominent part at the deliberations of the national synod held at Kilkenny in May–June 1642, which led to the establishment of the catholic confederacy. He sat on the supreme council as one of the six members for Ulster; in December 1642, he was one of the signatories to a ‘Disavowal of the doings of certain unauthorised persons pretending to be agents of the Council’ (HMC, Franciscan MSS, 227).
From autumn 1645 O'Reilly was a prominent supporter of the papal nuncio to Ireland, GianBattista Rinuccini (qv), although as archbishop he failed to prevent Rinuccini appointing Oliver Darcy (qv) and Patrick Plunkett (qv), clerics of Old English ancestry, to the dioceses of Dromore and Ardagh which had predominantly Gaelic Irish populations. In the upheavals following the first Ormond peace (1646) he was removed from the supreme council and never recovered his position. He retired to Co. Cavan and was not prominent again in confederate affairs until April 1649 when, with Heber MacMahon (qv), bishop of Clogher, he excommunicated the entire regiment of Sir Phelim O'Neill (qv). In November 1649 after the death of Owen Roe O'Neill (qv), he wrote a letter of recommendation for O'Neill's son Henry, to the marquess of Ormond (qv), royalist lord lieutenant, advising that ‘your excellency will (in time) find the gent deserving’ (Contemporary history, ii, 317). Following the annihilation of the Ulster catholic army at Scarriffhollis in June 1650, O'Reilly again took a leading role in the affairs of the catholics of Ulster. In September 1651 he urged the gentry of Ulster to hold out for the terms granted to Owen Roe O'Neill in negotiations with Ormond and in November he authorised a number of delegates to go from Ulster to Galway. In February 1652 he again excommunicated Sir Phelim O'Neill, this time for failing to attend a rendezvous of the remnants of the Ulster army.
By 1653 O'Reilly was the last catholic bishop remaining in Ireland. He died at Trinity Island, Co. Cavan, in February 1653, at the age of seventy-two. A prominent cleric in confederate affairs, he was more concerned with ecclesiastical matters than his contemporary Heber MacMahon. Described as ‘a godly and upright prelate’ in the Aphorismical discovery, O'Reilly left his mark as a reforming bishop.
O'Reilly financed the publication of the first volume of John Colgan's (qv) Acta sanctorum Hiberniae in 1645; Colgan dedicated the first volume to the archbishop, who had been supporting his work since 1642. A silver chalice made for Archbishop O'Reilly in 1628 is in Cavan cathedral.