Irvine, William (1734–1814), MP, Volunteer colonel, and freemason, was born 15 July 1734, the eldest son of Christopher Irvine (d.1755), of Castle Irvine, Co. Fermanagh, landowner, and his second wife, Elinor (d.1767), daughter of Audley Mervyn of Trillick, Co. Tyrone. In 1758 he was appointed high sheriff of Co. Fermanagh, a position that been held by his father and grandfather, Colonel Christopher Irvine (d.1723). He was also appointed high sheriff of Co. Tyrone in 1768, and elected MP for Ratoath, Co. Meath (1769–76).
During his first term in parliament he voted with the opposition, supporting Sir Lucius O'Brien's (qv) proposals for financial reform in 1771. He later supported a short revenue bill (1772), and bills for absentee taxation (1773) and opposing the taxation of the press (1773). In 1774 he voted against catholic relief. Anxious to represent his home county, he stood for Co. Fermanagh in 1776. Although a member of the established church, he received much of the popular presbyterian vote, but was defeated by aristocratic influence. Remaining active in politics, he was friendly with leading Patriots and became a prominent member of the Volunteers. Elected colonel of the Lowtherstown Masonic Volunteers, he chaired the Dungannon Volunteer Convention of 15 February 1782 which adopted resolutions in favour of legislative independence and catholic relief. In November 1783 he was a Fermanagh delegate to the Grand National Volunteer convention at the Rotunda, Dublin, which drew up proposals for parliamentary reform that were rejected by the Irish house of commons. In 1790 he again failed to be elected MP for Fermanagh but was elected for Ratoath (1790–97). He supported George Ponsonby (qv) in his unsuccessful attempt to be elected speaker of the Irish commons, voted for catholic relief in 1793 and 1795, and supported Ponsonby's proposals for parliamentary reform in 1797. During the 1790s he appears to have been friendly with leading Ulster radicals such as Thomas Russell (qv). He retired from politics in 1797.
He was a member of the RDS from 1775, and a prominent freemason, having been elected deputy grand master of Ulster in March 1776. In 1808 he became involved in the controversy that gripped the order following the expulsion of Alexander Seton for embezzling funds. He attended the Ormond Tavern meeting in Dublin in 1808 and, when the grand lodge of Ulster declared its independence from the grand lodge in Dublin, he was elected grand master of the secessionist province. This grand lodge or ‘grand east’ of Ulster existed until 1814 by which time most of the disaffected masons had re-aligned themselves with Dublin.
He was married twice: in December 1755 to Flora Caroline Cole (d.1757), daughter of John, 1st Baron Mountflorence; they had one son, who died in infancy. In February 1760 he married Sophia Lowther, daughter of Gorges Lowther of Kilrue, Co. Meath; they had eight sons and eight daughters. He died in Dublin in May 1814. There is a large collection of his papers in PRONI.