O'Connell, Sir John Robert (1868–1943), solicitor and priest, was born in Dublin on 12 February 1868, the only son of Thomas Francis O'Connell, solicitor, of 10 Mountjoy Square, Dublin, and his wife Maria, only daughter of Robert Francis Stein of Blackrock, Co. Dublin. He was educated at Belvedere College and TCD, where he graduated BA (1889), MA, and LLD in 1894. A vice-president of the College Historical Society, he was prominent in preparations for the TCD tercentenary celebrations. He was admitted as a solicitor in 1889, and practised in his father's firm of Thomas F. O'Connell and Son. A director of the National Bank, he was solicitor to the Dublin and South-Eastern Railway Company, and in 1924 vice-president of the Incorporated Law Society of Ireland.
His family had connections in Cork, and he was for a time a JP (magistrate) for Co. Cork. He was a member of both the UCC governing body and the senate of Dublin University, a fellow of the RSAI, an MRIA, and a vice-president of the Statistical and Social Inquiry Society of Ireland. When Isabella Honan, the benefactress of the Honan scholarships at UCC, died in August 1913, the Honan trust funds were bequeathed to O'Connell to be applied for charitable purposes in Cork. The following April O'Connell proposed to the president of UCC, Bertram Windle (qv), that the moneys be applied to the establishment of a hostel for catholic lay students. In addition the Honan bequest would be used to complete the biological institute and the hydraulic department of the engineering laboratories. O'Connell was knighted in 1914. Five years later, when Windle privately led a deputation from UCC to the viceroy, Lord French (qv), he included O'Connell, which led Alfred O'Rahilly (qv) to comment that ‘Sir John O'Connell is a Trinity College graduate, lives in Killiney and has no right to interfere with the matter at all’ (quoted in Murphy, The college, 206). He stood as independent candidate in Dublin South in the 1922 general election, but received the second lowest number of first preferences.
O'Connell was a prolific writer of pamphlets on civic and, later, religious subjects. These included his address as auditor of the Solicitors’ Apprentices Debating Society, A plea for a peasant proprietary for Ireland (1888), The problem of the Dublin slums (1913), pamphlets on dominion self-government in 1917, including An Irish nationalist's plea for dominion self-government, and pamphlets on the Honan chapel at UCC (1916), Saint Thomas More (1935), and Devotion to the Sacred Heart of Jesus, its history and its practices (1940).
In 1901 he married Mary, daughter of Thomas Scally of Deepwell, Blackrock, Co. Dublin, who died in 1925. There were no children of the marriage. After her death he retired from legal practice and sold their home at Ard Einin, Killiney; his library was described in the auction catalogue as including memoirs, poetry, history, art and belles lettres, theological literature, Irish literature, miscellaneous literature, and old maps of Ireland. He entered the Benedictine monastery at Downside in Somerset, but in 1929 was ordained a secular priest by Cardinal Bourne of Westminster. He served in the Westminster diocese, for some years as a curate at St Patrick's church, Soho. In 1929 he was made a knight grand cross of the Order of the Holy Sepulchre by Pope Pius XI for services to the work, mission and schools of the Latin patriarchate in Palestine and Transjordan.
He died 28 December 1943 at Brockenhurst, Hampshire, and was buried 5 January 1944 at Glasnevin Cemetery, Dublin.