Cleland, John (1755–1834), Church of Ireland clergyman and land agent, was the second son of Moses Cleland, a Co. Down gentleman. He attended Glasgow University, graduating MA (1777), which supports the belief of Francis Plowden (qv) that he was brought up a presbyterian. His first employment was as tutor to Robert Stewart (qv) (1769–1822), the future Viscount Castlereagh, elder son of a presbyterian landowner in north Co. Down, Robert Stewart (qv) (1739–1821), with whose family at Mount Stewart, near Newtownards, he was acquainted from an early age. Robert Stewart senior was MP for the county (1771–83) and was later created Baron Londonderry (1789), Viscount Castlereagh (1795), earl of Londonderry (1796), and marquess of Londonderry (1816).
Cleland's fortunes rose with the Stewarts', thanks to their patronage. On 2 February 1781 he was ordained into the ministry of the established protestant church. At about the time Robert Stewart junior went up to Cambridge (1787) Cleland became agent for the Stewarts’ extensive estates. In 1789 he was appointed to the benefice of perpetual curate (in effect rector) of Newtownards. In the 1790s he was also agent to a landowner at Saintfield, Nicholas Price (1754–1840), a close relative of the Stewarts. Among the largely presbyterian tenantry Cleland had a reputation for sharp practice. He was also a very active magistrate. He was the model for ‘Squire Firebrand’ in an anti-government satire by a presbyterian minister, James Porter (qv), serialised in the Northern Star (May–December 1796), republished as Billy Bluff and the squire (1797), and reprinted as late as 1840. By thus putting words into Cleland's mouth, Porter ‘sought to expose the hypocrisy of tyranny masquerading as religion’ (Curtin).
In October 1796 an attempt was made on Cleland's life as he was leaving the estate office at Newtownards. He kept Castlereagh, who from 1790 was MP for Co. Down and from July 1797 effectively chief secretary, informed of local United Irish activity. His greatest success as a law enforcer was in getting a disaffected United Irishman living at Saintfield, Nicholas Mageean (d. 1818?), to identify local United Irishmen and divulge their plans for insurrection. This information he transmitted to Castlereagh in Dublin (April 1797 to June 1798), thereby fatally weakening the United Irish organisation in its heartland. In 1798 he was an officer in the Newtownards yeomanry and was judge-advocate at trials held there. One person convicted was Porter, who in consequence was hanged. Cleland tried to secure the indictment for high treason of William Steel Dickson (qv), the presbyterian minister at Portaferry whom, according to Plowden, he had once ‘procured . . . to write for him his thesis upon which he was ordained by the bishop of Dromore’ (Hist. Ire., introduction, 64).
Cleland accumulated great wealth from his land agencies and from sinecures in the established church – he became also chancellor of Lismore (1796) and precentor of Armagh, to which was joined the rectory of Killeavy, Co. Armagh, worth £1,200 p.a. (1802), though later he gave up Newtownards (1810). He married (1805) Esther, daughter of Samuel Jackson and his wife, Margaret (née Vateau), and heir to Mount Pleasant, a property situated at Dundonald, between Newtownards and Belfast. The couple went to live there some years later, began improving it, and about 1830 changed its name to Stormount (later Stormont). John Cleland died there 25 June 1834 aged eighty. Their son Samuel Jackson Cleland (1808–42) and his son John Cleland (1836–93) continued the improvements. In the late 1850s the latter built, in Scottish baronial style, the castle that in the 1920s became the seat of the Northern Ireland government.