O'Kelly, Dominic (c.1613–1669), Dominican priest and provincial, was born in the diocese of Elphin. There is a conflict of views as to his parentage. According to one source he was the son of William Reagh O'Kelly of Skreen, Co. Roscommon, and had one brother, Conor, who was also a Dominican. Thomas Burke (qv), however, claimed that he was ‘of the respectable house of Ballenlass, Co. Galway’. He received the Dominican habit in Ireland c.1625, before departing for Spain for his ecclesiastical studies and priestly ordination, possibly in Catalonia or Valencia. He returned to Ireland in 1643 and was a member of the Roscommon community in 1644, as is shown by the survival there of his copy of Ludovicus de Tena's Isagoge in totam sacram scripturam (Barcelona, 1620). He was honoured by a provincial chapter with the titles of lector of philosophy and preacher general. About 1650 he became prior of Portumna, where Ulick Burke, marquess of Clanricard and lord deputy (1650–52), resided in his fortified mansion and whom he advised. After Clanricard accepted terms that banished him from Ireland (June 1652), O'Kelly was among those catholic clergy who underwent imprisonment and subsequent exile.
In June 1655 O'Kelly received missionary faculties to return to Ireland, but was unable to do so owing to the Cromwellian persecution. He was appointed prior of Holy Cross College, Louvain, before 8 January 1659, but resigned in October 1660. He was still at Louvain in 1663–9, during which time he was involved in diplomatic correspondence concerning the divisive activities of the controversial Franciscans Peter Walsh (qv) and James Taaffe (qv). He was postulated for the diocese of Elphin twice and for Achonry once. Named Irish provincial on 23 March 1669, he left Louvain immediately and reached London by April, but he died a few months after his arrival in Dublin. During O'Kelly's brief term of office, John Reynolds alias Landy, the Dominican supporter of Peter Walsh, made his submission. The Irish Dominican chapter held at Dublin on 16 November 1669 noted O'Kelly's death.
O'Kelly was the maternal uncle of another Dominican priest, John Baptist O'Berne (c.1620–1687), ‘eldest son of the noble O'Berne’ (Epil. Chron. ed. A. Coleman (1902), 263), and likewise a member of the Roscommon community. O'Berne studied at Salamanca and Atocha, Madrid, taught philosophy at Prague, and later was made regent of studies at Holy Cross, Louvain, before returning in 1661 to an eventful career in Ireland.