Bagwell, John (1752–1816), landowner and MP, was the only son among four children of William Bagwell (c.1728–1756) of Clonmel, Co. Tipperary, presbyterian, banker, merchant, and MP for Clonmel (January–July 1756), and Jane Bagwell, daughter of John Harper of Belgrove, Co. Cork. Raised by his mother's family as a presbyterian, he later conformed to the established church, and entered Christ Church, Oxford (10 March 1768), graduating MA 22 June 1771. He amassed a large fortune by building flour mills and bought property in Co. Cork and Co. Waterford and the estate of Marlfield near Clonmel. His family's links with trade were often mocked and his occupation earned him the nicknames ‘Old Bags’ and – as colonel of the militia – ‘Marshal Sacks’. Colonel of the Clonmel Independent Volunteers in 1792, he supported Patriot demands for free trade and legislative independence, and in 1783 was a founder of Constitutional Associating Freeholders, formed in Clonmel to press for parliamentary reform. He unsuccessfully contested Cork city in parliamentary elections in 1776 and 1783. He was governor (1792–1816) and high sheriff (1793–4) of Co. Tipperary, colonel of the county militia (1793–1805), and MP for the county (1792–1800, 1801–6), initially opposing the government. In the 1792 election he unseated the pro-catholic Francis Mathew (qv), and for the next few years Bagwell supported catholic relief to broaden his narrow base of support.
Having been on the receiving end of Whiteboy agrarian protests in Tipperary on several occasions, he favoured taking a hard line with disaffection, and during the 1798 rebellion he gave his militia regiment free rein to take severe reprisals against suspected rebels. During the union debates he changed his mind twice, much to the annoyance of the viceroy, Cornwallis (qv). Having first promised to support the union, and exacted a good price from government, he then opposed it in 1799, claiming that he had misjudged local opinion and the opposition had made him a better offer; but eventually in 1800 he and his two sons returned to the pro-union camp for fear of forfeiting everything. In 1800 he bought the lordship and manor of Clonmel, and packed the town corporation with his nominees.
At Westminster, he and his sons generally supported government (with the exception of the Grenville ministry, 1806–7). He spoke regularly in parliament: Thomas Creevey, an English MP, described Bagwell and Isaac Corry (qv) as ‘the only Irish I have heard that are commonly decent’ (Thorne, 104). He supported the incoming Pitt administration (1804) in return for positions for his sons: a deanery for Richard, a full-pay army commission for John, and the colonelcy of the Tipperary militia for William. Interested in many social issues, he voted for the establishment of lunatic asylums in Ireland, better provision for the families of military volunteers, Irish poor relief, and the abolition of the slave trade. Having opposed catholic relief at Westminster, he failed to be elected for Co. Tipperary in 1806 and 1812. He unsuccessfully sought a peerage or a place on the privy council: in February 1812 the viceroy advised against raising ‘a low man’ with such vulgar nicknames to the peerage, despite Bagwell's £18,000 a year. He died 28 September 1816.
He married (4 February 1774) Mary Hare of Ennismore, Co. Kerry, sister of William Hare (1751–1837), 1st earl of Listowel; they had four sons and four daughters. His second son, Richard (1778–1826), was MP for Cashel, Co. Tipperary (1799–1800, January–November 1801), and dean of Kilmacduagh (1804–6) and Clogher (1806–26); his fourth son, John (c.1780–1806), lieutenant-colonel in the 6th Royal Dragoons, was MP for Cashel (1801–2). His eldest son, William Bagwell (1776–1826), was educated at Westminster and in Germany, and became lieutenant-colonel of the Tipperary militia (1794). He was MP for Rathcormack, Co. Cork (1798–1800), and took his father's line on the union. At Westminster he represented the borough of Clonmel (1801–19), which his father had bought in 1800, and Co. Tipperary (1819–25), and generally supported the government. He became mayor of Clonmel (1804–5), colonel of the Tipperary militia (1805–26), joint muster master general for Ireland (1807–26), governor of Co. Tipperary (1807), a trustee of the linen board (1808–26), and an Irish privy councillor (1810–26). He consistently voted against sinecure reform and parliamentary reform; on catholic emancipation, he opposed it until 1810, abstained 1810–13, and voted in favour thereafter, indicating his designs on the county seat. On 24 February 1813 he presented a petition from Tipperary protestants in favour of catholic emancipation with certain safeguards. William died 4 November 1826 at East Grove, near Cobh, Co. Cork; he never married and the family estates devolved on his nephew John Bagwell (1811–83), liberal MP for Clonmel (1857–74).