Kelly, Matthew (1814–58), catholic priest and church historian, was born 24 September 1814 in Maudlin St., Kilkenny, the eldest son of James Kelly and his wife, Margaret (née Sanphy). The Kellys were a clerical family: an uncle of Matthew, Patrick Kelly (1779–1829), was bishop of Waterford; a grand-uncle, Edward Nolan (d. 1851), was dean and vicar-general of Ossory; a brother, John, also became a priest; and a sister was a Presentation nun at Midleton, Co. Cork.
At an early age Matthew Kelly entered the local diocesan college. Intent on an ecclesiastical career, he matriculated at Maynooth College (25 August 1831), where he excelled at his studies and took the prize essay at the Dunboyne Establishment (a department of Maynooth). He was appointed a professor of philosophy at the Irish College in Paris in 1839. He returned to Ireland to become professor of English and French at Maynooth (from 4 November 1841) and retained this post until he moved to the chair of ecclesiastical history (20 October 1857). As a teacher he was noted for his ‘sweetness and urbanity of manner’ (Murphy).
Kelly's interest in history may have begun with his awareness that the house next to the one where he was born was that in which the historian Thomas de Burgo lived and died. He was a frequent contributor to the Dublin Review (1842–55), his most notable contribution being a critique of a work of Henry Joseph Monck Mason (qv), The testimony of St Patrick against the false pretensions of Rome (1846). He translated and edited for the Celtic Society (of which he was a founder member) a work of John Lynch (qv), Cambrensis eversus (1848–51), and edited and published the Apologia pro Hibernia of Stephen White (qv) (1849), the Historiae catholicae Iberniae compendium of Philip O'Sullivan Beare (qv) (1850), and Calendar of Irish saints: the martyrology of Tallagh (1857). He was awarded a DD in 1854. In declining health, though only in his early forties, he superintended publication of the work of Laurence Renehan (qv), Collections on Irish church history (1861). During the summer before his death he visited St Gall and other places on the continent of interest to Irish ecclesiastical historians.
Matthew Kelly died 30 October 1858 and was interred in the Maynooth College burial ground. Some of his writings were edited by a colleague, a future bishop of Kerry, Daniel McCarthy (1822–81), and published (in some cases republished) as Dissertations chiefly on Irish church history (1864).