O'Donnell, Hugh (1739–1814), priest, was born in Glenarm, Co. Antrim, eldest son of Roger O'Donnell (1707–94), farmer, and his wife Eleanor (née Magill) (1716–85). He was educated by his father and by a Franciscan friar at a hedge school before departing in 1760 for the Irish College at Salamanca in Spain, where he took holy orders. In 1768 he was appointed curate of Derryaghy, Belfast, to assist the aged and infirm Fr John Mullan. The penal laws being still in force, though beginning to relax, his first congregation allegedly met under an old thorn bush in what is still called Friar's Bush graveyard. He obtained a lease on premises in Mill St., where he established a mass house. It was cramped and the only entrance was through a narrow lane called ‘Squeeze-gut Entry’, but he was said to have been the first priest to perform his duties publicly in Belfast since the penal period began. On Fr Mullan's death (1772), he took over as parish priest and became a prominent figure in Belfast. A tolerant man, who at a local banquet proposed a toast to ‘religion without priestcraft’ (Owen, 118), he gave sermons preaching brotherly love and the uniting of all ‘true and faithful Irishmen, for the good of their king and country’ (Belfast News Letter, 19–22 Mar. 1782), and praised those presbyterians who had spoken out against the penal laws. These views found favour with the Belfast Volunteers, who on 30 May 1784 marched in full dress to the inaugural mass at St Mary's in Chapel (formerly Crooked) Lane and made a donation of £84 to the new church. The pulpit was presented by the Rev. William Bristow (qv), vicar of Belfast, and numerous other protestants also attended mass; the event made headlines in the national press. The Belfast News Letter (1 June 1784) said the Volunteers’ attendance symbolised the ‘patriotic union’ between the two faiths, and it denounced past administrations for their policy of using religious differences in Ireland to strengthen their position.
As chairman of a political meeting held by the catholics of Belfast in 1792, O'Donnell paid tribute to the reforming and non-sectarian ideals of the United Irishmen. However, he did not support its transformation to a revolutionary organisation and largely remained out of politics in the 1790s. During the years of violence, his parish church at Derryaghy was burned down (mass was celebrated in a barn for the next four years), as was the Rock chapel which was not replaced until 1829. A cultured man, O'Donnell was among the first members of the Belfast Society for Promoting Knowledge (later the Linen Hall library) and in 1795 was elected to its management committee. In 1809, while fund-raising for another church, he allegedly received a generous donation of £100 from Lord Castlereagh (qv). This church opened in Donegall St. in 1815.
O'Donnell died at his sister's home in Springbank, near Hannastown, on 1 January 1814, having resigned his parish in summer 1812. His body was removed to St Mary's and thence to Glenarm, where it was buried with his parents in the Church of Ireland graveyard, beside the ruins of a Franciscan friary.