Kinghorn was born at Gateshead-on-Tyne, County Durham, on 17 January 1766.
His father, David Kinghorn (3 October 1737 – 18 February 1822) was a shoemaker and Baptist preacher at Newcastle-on-Tyne, who was ordained on 1 May 1771 as minister of a Baptist congregation at Burton-Bishop, East Riding of Yorkshire, where he remained till July 1799, when he retired to Norwich.
Joseph was his eldest son by his second wife, Elizabeth (d. 25 January 1810, aged 72), second daughter of Joseph Jopling of Satley.

After four years' schooling, Kinghorn was taken on trial as apprentice to watch- and clock-making at Hull in 1779, but in March 1781 became a clerk in the white-lead works at Elswick, Northumberland of Walker Fishwick & Co. On 20 April 1783 he was baptised by his father at Burton-Bishop, and considered entering the ministry.
He made the acquaintance of Robert Hall, and had thoughts of joining him at the University of Aberdeen, but on 20 August 1784 he entered Bristol Baptist Academy, under Caleb Evans.
His closest friend there was James Hinton (1761–1823).

On leaving the academy, Kinghorn ministered for some months (from May 1788) at Fairford, Gloucestershire.
He received an invitation to Norwich, because of a business connection between Richard Fishwick who worked at his old firm, and Thomas Hawkins, both Baptists, Hawkins belonging to the congregation at St. Mary's Chapel, Norwich.
On 27 March 1789 he settled in Norwich, and was ordained on 20 May 1790.

Kinghorn was famed for his preaching, which was noticed by Edward Irving.
On the liberal side in his politics, though a moderate, he did not bring them into his discourses.
He looked to Biblical prophesy to interpret current affairs.
William Wilkin Wilkin (1762–1799) of his congregation was a personal friend, as well as a radical.
When Wilkin died in 1799, Kinghorn brought up and educated his son Simon Wilkin.

From 1790 Kinghorn was a member of the Norwich Speculative Society, entering the intellectual life of the city, of which William Taylor was the effective leader.
He defended Christianity at the Tusculan School, another debating club, in 1794, where he was strongly opposed by Charles Marsh.

In 1804 Kinghorn was invited to become head of the Northern Baptist Academy, then being set up in Bradford, but he preferred pastoral work.
His old chapel was replaced in 1811 by a new structure on the same site.
In a controversy with Robert Hall, which began in 1816, Kinghorn took the side of close communion, requiring adult baptism a condition of participation in the Lord's Supper.
He made mission journeys to Scotland in 1818 and 1822.

In later life Kinghorn devoted much time to Hebrew and rabbinical studies.
He died unmarried on 1 September 1832, and was buried on 7 September in the vestibule of St. Mary's Chapel.
Joseph John Gurney spoke at his funeral, where the sermon was preached by John Alexander, minister of Prince's Street congregational church.
Kinghorn was born at Gateshead-on-Tyne, County Durham, on 17 January 1766. His father, David Kinghorn (3 October 1737 – 18 February 1822) was a shoemaker and Baptist preacher at Newcastle-on-Tyne, who was ordained on 1 May 1771 as minister of a Baptist congregation at Burton-Bishop, East Riding of Yorkshire, where he remained till July 1799, when he retired to Norwich. Joseph was his eldest son by his second wife, Elizabeth (d. 25 January 1810, aged 72), second daughter of Joseph Jopling of Satley.
After four years' schooling, Kinghorn was taken on trial as apprentice to watch- and clock-making at Hull in 1779, but in March 1781 became a clerk in the white-lead works at Elswick, Northumberland of Walker Fishwick & Co. On 20 April 1783 he was baptised by his father at Burton-Bishop, and considered entering the ministry. He made the acquaintance of Robert Hall, and had thoughts of joining him at the University of Aberdeen, but on 20 August 1784 he entered Bristol Baptist Academy, under Caleb Evans. His closest friend there was James Hinton (1761–1823).
On leaving the academy, Kinghorn ministered for some months (from May 1788) at Fairford, Gloucestershire. He received an invitation to Norwich, because of a business connection between Richard Fishwick who worked at his old firm, and Thomas Hawkins, both Baptists, Hawkins belonging to the congregation at St. Mary's Chapel, Norwich. On 27 March 1789 he settled in Norwich, and was ordained on 20 May 1790.
Kinghorn was famed for his preaching, which was noticed by Edward Irving. On the liberal side in his politics, though a moderate, he did not bring them into his discourses. He looked to Biblical prophesy to interpret current affairs. William Wilkin Wilkin (1762–1799) of his congregation was a personal friend, as well as a radical. When Wilkin died in 1799, Kinghorn brought up and educated his son Simon Wilkin.
From 1790 Kinghorn was a member of the Norwich Speculative Society, entering the intellectual life of the city, of which William Taylor was the effective leader. He defended Christianity at the Tusculan School, another debating club, in 1794, where he was strongly opposed by Charles Marsh.
In 1804 Kinghorn was invited to become head of the Northern Baptist Academy, then being set up in Bradford, but he preferred pastoral work. His old chapel was replaced in 1811 by a new structure on the same site. In a controversy with Robert Hall, which began in 1816, Kinghorn took the side of close communion, requiring adult baptism a condition of participation in the Lord's Supper. He made mission journeys to Scotland in 1818 and 1822.
In later life Kinghorn devoted much time to Hebrew and rabbinical studies. He died unmarried on 1 September 1832, and was buried on 7 September in the vestibule of St. Mary's Chapel. Joseph John Gurney spoke at his funeral, where the sermon was preached by John Alexander, minister of Prince's Street congregational church.
Joseph Kinghorn