Cantwell, John (1792–1866), catholic bishop of Meath, was born 25 December 1792 at Rahan, King's Co. One of the family of at least six children of Edward Cantwell and his wife Catherine, he was briefly a student at the diocesan seminary, St Finian's, at Navan, Co. Meath (from February 1808), before entering Maynooth College (1809). On his ordination to the priesthood (27 December 1815) he was appointed sub-dean at Maynooth; soon he was junior dean (February 1816) and some months later (27 June) dean at a salary of £121 p.a. From June 1820 he was parish priest of Kilbeggan, Co. Westmeath. On 21 September 1830, Cantwell was consecrated bishop of Meath in the chapel at Mullingar, Co. Westmeath. His promotion to this large, important diocese at the age of 37 was, wrote the archbishop of Armagh, Patrick Curtis (qv), ‘on account of his superior knowledge of theology and of the great exertions and abilities he has displayed’ (Connell, Cantwell, 12). He set about moving the seat of his diocese from Navan to Mullingar. During his episcopate he built many chapels and convents, most notably the cathedral at Mullingar that he formally dedicated to St Mary (15 August 1836).
As a parish priest he had supported the political agitation of Daniel O'Connell (qv) and taken an active part in the Westmeath election of 1826. His political concerns and activities continued after 1830. Always a close associate of O'Connell, he was one of the first bishops to declare for repeal of the union with Great Britain. In 1843 – the ‘year of Repeal’ – he spoke at the repeal banquet at Trim (19 March) and the monster meetings at Kells (23 April) and Mullingar (14 May) as well as the national convention at Tara (15 August). In the 1840s he was a critic of the poor law while serving on the board of Mullingar Lunatic Asylum. When the government introduced a charitable bequests bill (June 1844), Cantwell, like O'Connell, opposed it strongly and publicly on the ground that a majority of charitable bequests commissioners would probably be protestants; he was publicly checked when the catholic archbishops of Armagh and Dublin, William Crolly (qv) and Daniel Murray (qv), accepted appointment as commissioners. Similarly he opposed the queen's colleges bill (1845), subsequently making great efforts with episcopal colleagues, Paul Cullen (qv) and John MacHale (qv), to found a Catholic university.
In the 1850s he was supportive of the Irish Tenant League, in which many of his priests were active. He was supportive too of independent candidates representing catholic and tenant interests who stood in the Meath and Westmeath constituencies at the general election of 1852, one of them Frederick Lucas (qv) in whose honour he addressed a league banquet at Navan (17 January 1854). If Cantwell was a nationalist, his nationalism was only for the Irish: writing to Cullen in 1848 he referred to Italian nationalists as the pope's ‘ungrateful and barbarous subjects’ and after the successes of Italian nationalists in the papal states in 1860 he expressed to Tobias Kirby (qv) his wish that the ‘paternal rule of the holy father would soon be restored’ (ibid., pp 31, 32). Ill health brought about the appointment (28 August 1864) of a co-adjutor, Thomas Nulty (qv), who eventually succeeded him. John Cantwell died 11 December 1866. Unlike his predecessor, Patrick Plunket (qv), he was highly assertive in promoting the interests of the catholic church, an attitude he no doubt encouraged in Nulty, his favourite for the succession. A commemorative bust of Cantwell is in the Cathedral of Christ the King, Mullingar, the new edifice that in 1939 superseded, on the same site, the cathedral he had built in the 1830s.