Kelburn, Sinclare (Sinclair) (1754–1802), presbyterian minister and radical, was born in Dublin, the only son of the Rev. Ebenezer Kelburn, minister of the Plunkett St. (latterly Ormond Quay) presbyterian church in Dublin, and Martha Kelburn (née Sinclare). In November 1769 he entered TCD, and graduated BA (1774). He then entered Edinburgh University, where he studied theology and medicine. Deciding on a clerical career, he was ordained 8 February 1780 as a minister of the Third Presbyterian congregation of Belfast and was appointed as the assistant of the Rev. William Laird at the Rosemary St. church. Among his flock were Henry Joy (qv), Henry Joy McCracken (qv), and Mary Anne McCracken (qv), and he quickly established a reputation as an able preacher.
A supporter of parliamentary reform and catholic emancipation, he became an active Volunteer, attending the Dungannon convention (1782), and in November 1784 representing Belfast at the Grand National Convention in Dublin with Henry Joy. In July 1784, with Waddell Cunningham (qv) and Joy, he sat on a committee charged with drafting a memorial to the king calling for a gradual extension of suffrage to catholics. He was an able theologian of the evangelical Old Light tradition, as shown in his first publication, The morality of the Sabbath defended (Belfast, 1781). Kelburn often wore his Volunteer uniform, and his energetic preaching to a Volunteer congregation was part of Belfast's political folklore: ‘as the Christian soldier enforced his patriotic exhortations by action and gesticulation, not only did the preacher's own musket rattle, but his armed audience characteristically expressed their approbation by striking the butt of their muskets on the meeting-house floor’ (Witherow, 243). His later publications included The duty of preaching the Gospel explained and recommended (Dublin, 1790) and The divinity of our Lord Jesus Christ asserted and proved (Belfast, 1792). This latter publication, his most important theological work, was reprinted in 1821.
In January 1792 he was one of the founding members of the Northern Star. An associate of Thomas Russell (qv) and William Steel Dickson (qv), he often wrote articles calling for a reform of parliament. Owing to the large attendance, a political meeting convened on 28 January could not be held in the Town House and so repaired to his New Meeting House. R. R. Madden (qv) stated that Kelburn was a founding member of the United Irishmen but, despite his often inflammatory speeches, there is no evidence that he ever took the test. However throughout the 1790s he remained politically active and sympathetic to the catholic cause, reading out the declaration of the Catholic Committee at a Belfast town meeting and attending a dinner given by the catholics of Newry on 19 August 1792 in honour of Theobald Wolfe Tone (qv) and John Keogh (qv). As one of several presbyterian radicals associated with the reformist politics of the previous decade, his name featured on a list of houses to be assaulted by dragoons in 1793.
In early April 1797 he was arrested at his home for high treason, on suspicion of being involved with the United Irishmen. He was brought to Dublin with Dr Alexander Crawford (qv) of Lisburn, and they were imprisoned in Kilmainham gaol, where Henry Joy McCracken was also held. The informer Edward Newell (qv) later admitted that it was he who had denounced Kelburn. Many members of Kelburn's congregation were convinced that although he supported reform he had never become a United Irishman, and a petition, signed by 162 members of the Rosemary St. congregation, was sent to Earl Camden (qv) stating this and demanding his release.
Kelburn was at the side of James Dickey at his execution on 26 June 1798 and, although ill, insisted on ministering to Henry Joy McCracken when he learned that he was to be hanged on 17 July 1798; he was overpowered by his feelings at the loss of his young parishioner. By the time of his release (1799) his health had broken down and he had lost the use of his limbs. He was forced to resign his ministry, and attended the 1800 synod at which this was announced, after which his congregation presented him with a commemorative piece of plate. Little is known of his marriage, save that his wife's name was Frances. He died 31 March 1802 at Beersbridge, Belfast, aged 48, and was buried at Castlereagh cemetery, Co. Down. A memorial was later raised at his grave by members of his family and congregation. There is a miniature portrait of him in the lecture room of the Rosemary St. presbyterian church, Belfast.