O'Connor, Daniel (1786–1867), Augustinian priest and bishop, was born 6 July 1786 in Limerick city; nothing is known of his family. He was educated in schools in Limerick city, and received religious instruction from an early age. In 1807 he entered the Augustinian noviciate in Galway, and was professed the following year. He was ordained a priest in 1810, having studied theology under Dr James Warren Doyle (qv) and Dr Martin Crane at New Ross College, Co. Wexford. O'Connor was at New Ross c.1809–1813, but moved to the Augustinian convent, Cork, in 1813. As an Augustinian friar and provincial, he held rallies for four years to rebuild Dungarvan church in Co. Waterford, and achieved success c.1823. In 1829 he led a delegation to London, which included the Dominican priest John Leahy and Edmund Ignatius Rice (qv), founder of the Christian Brothers, to lobby the government over a clause in the catholic emancipation bill which would have prohibited the religious orders. O'Connor was the chief negotiator with the duke of Wellington (qv) and Sir Robert Peel (qv), and received an assurance that the clause would only be enforced by the attorney general – an action, they believed, that would never be taken.
Doyle recommended O'Connor to the Holy See in 1834 to become the first Irish catholic bishop of Saldes, India. He was consecrated bishop (3 August 1834) in Cork. He had considerable difficulty in raising funds to finance his mission, but was assisted by a donation from an Indian princess and a fund-raising tour throughout the Irish dioceses. Eventually he collected £942, including a gift of £10 from the Marchioness Wellesley, of the viceregal lodge, Phoenix Park. He set sail for India on the Duke of Sussex (8 May 1835) from Gravesend, with other clergymen, such as his secretary and vicar general, Patrick Moriarty (1804–75), and several thousand books, on a journey that took ninety-three days by way of the Cape of Good Hope. On arrival at Madras he was made vicar apostolic of Madras and titular bishop of Saldes. O'Connor faced the difficult prospect of gaining the government's support, but he approached the issue diplomatically and in 1836 the civil authorities recognised him as the only legal intermediary between the local government and the court of Rome. At a pastoral level, his chief aim was to suppress a local schism that had arisen, and he also established female education in Madras in 1837, to which the Hindus were opposed. His workload was heavy: a gruelling routine and a dispute with the Capuchin fathers in India led in 1837 to a severe stroke, which paralysed his left side.
In 1838 he was appointed vicar apostolic of Meliapore, and commenced a lawsuit against the Augustinian friars for the recovery of the church property of Meliapore, as they refused to recognise Rome's authority. To ease O'Connor's workload, Fr Patrick Joseph Carew (1799–1855) arrived at Madras in 1839 to assist him. That year O'Connor addressed an important circular to the vicars apostolic of India, and their unanimous answer reproved the schismatics. He also translated and published Dr Butler's general catechism in the Tamil language, and drew up an important paper on the affairs of Ceylon. In 1839 O'Connor contracted jungle fever on a journey from Porto Novo to the south of Madras, and became very disorientated. He had intended to make an intensive tour of India, but was in a dangerous state of health, and funds were raised to finance his voyage to Rome in 1840.
In 1841 he resigned his vicarate at Rome, received a pension, and was appointed domestic prelate to the throne of the sovereign pontiff at Rome on 15 February 1842. He returned to Ireland that year, and spent three months in Callan recovering his health before moving to Dublin, where he spent the remainder of his life at St John's Lane, Dublin, becoming known as the ‘St John's Lane bishop’. O'Connor remained active in visiting the poor and consoling the sick. He also took a keen interest in the repeal movement, visited Daniel O'Connell (qv) in Richmond prison in 1844, and celebrated a special mass on his release.
In 1858 O'Connor laid the foundation stone of the retreat house for the Oblate Fathers in Inchicore, Dublin. He purchased a site near James's Harbour in 1862, and built a house, which he called Mountain View. His garden was called ‘Limbo’, because it was traditionally known as the burial place of unbaptised children. When the Fenian leader James Stephens (qv) escaped from Richmond prison in 1865, he went to O'Connor, who allowed him to flee through a tunnel leading from his cellar. O'Connor died 19 July 1867, and was buried in the Augustinian grave at Glasnevin cemetery. His papers are held in the Irish Augustinian Provincial Archives at Ballyboden, Dublin.