McCabe, Thomas (1740?–1820), watchmaker, businessman, and United Irishman, was born probably at Lurgan, Co. Armagh, the eldest of four sons of Patrick McCabe (1708?–85), a clock- and watchmaker, and his wife, Mary (née Maziere) (1717?–1801). Taking up their father's trade, he and his brother William started up in business in Donegall Street, Belfast (1762). William moved later to Lisburn, Co. Antrim, and then to Newry, Co. Down, where he became a Volunteer and died in 1785. Another brother, John, was a clockmaker in Dublin until he emigrated to Baltimore in Maryland (1772); another, James (1748?–1811), moved to London and established the House of McCabe, whose fame as clock- and watchmakers reached India.
Thomas McCabe did not confine himself to his trade but engaged also in various business ventures and philanthropic activities. It was he who, with Robert Joy (qv), encouraged by Nicholas Grimshaw (qv), had introduced the cotton industry to Belfast), and installed machinery for spinning cotton in the Belfast poorhouse (1779). McCabe, Joy, his brother Henry Joy (d. 1789), and their brother-in-law John McCracken formed a partnership that in 1783 employed 150 persons in the cotton trade on the Lancashire model. The firm moved to Rosemary Lane (1784), increased its workforce to 500 (1785), and built a mill at the Falls, the first of its kind in Ireland to be powered by water (1787). McCabe also had a financial stake in the glassworks of John Smylie established at Ballymacarrett, just across the Long Bridge in Co. Down (1785). Although he eventually withdrew from the partnership with the Joys and McCracken (1788), he continued his interest in the cotton trade. He and an Englishman, William Pearce, invented an improved loom for weaving cotton and linen, but its development proved impossible after their application to the Irish parliament for a grant was rejected (February 1791).
Throughout the 1780s McCabe's horological business flourished. Objecting to the gold assay act of 1783, which required dealers in gold, silver, and jewels (as he was also) to register at the Goldsmiths’ Hall in Dublin, McCabe erected at his shop (which was first in Donegall Street, and then transferred to North Steet by 1790) a sign reading ‘An Irish slave, licensed to sell gold and silver’. McCabe was a freemason (a member of lodge no. 684) and a Volunteer (a captain in the Belfast regiment). By the 1790s he was well known for his liberal political opinions and as early as February 1791 became acquainted with Thomas Russell (qv) and Theobald Wolfe Tone (qv); he was a member of the committee that planned the formation of the Belfast Society of United Irishmen and took the chair at the inaugural meeting (18 October 1791). After the government moved to suppress the Volunteer movement (February 1793), McCabe had some part in secreting six field cannon belonging to the Belfast Volunteers, and suffered for his activities when his premises were damaged by rioting soldiers (9 March). According to William Tone (qv), ‘he would never allow his windows to be repaired, but kept them in their shattered state as a monument’. He was said to have gone to London to see the English radical John Thelwall and to have circulated Paine's Age of reason (1795) among workmen. But Martha McTier (qv) was dismissive of McCabe, noting in a letter to her brother (16 November 1793) that he ‘had just been reading Godwin, a book which I fear will be of no great use to enthusiastic minds of little depth’ (Agnew (ed.), i, 575).
By 1796 McCabe was in financial difficulty and had withdrawn from political activity. He seems to have played no part in the radicalised and militarised United Irish movement that brought about the rebellion of 1798. He died 5 March 1820 at Belfast, aged eighty. With his first wife, Jean (d. 1790), daughter of John Woolsey, a merchant at Portadown, Co. Armagh, he had three sons, Thomas McCabe (who died before 1815), James (who died young), and William Putnam McCabe (qv), as well as a daughter, Jean Maria, who married James Coleman (d. 1866), a wine merchant in Donegall Street, Belfast. Thomas McCabe's second marriage (October 1793) was to Isabella (1749?–1837), daughter of Thomas Read, a maltster at Lurgan. Thomas McCabe the younger, a friend of Russell, was a partner in the cotton manufacturing firm of Dickey & Sons of Randalstown, Co. Antrim, and later foreman in Orr's Mill, Stratford-on-Slaney, Co. Wicklow. The McCabes’ house and small farm in Belfast, Vicinage, on the Antrim Road, acquired before 1790, was sold in 1832 to the catholic bishop, William Crolly (qv), who built on the site a diocesan college, St Malachy's.