John Foster (1770–1843) was an English Baptist minister and essayist.
The son of a weaver, born in Halifax, Yorkshire, and educated for the ministry at the Baptist college in Bristol, Foster served as a minister for a number of years. Becoming a full-time writer, he contributed nearly 200 articles to the Eclectic Review. His works include Essays, in a Series of Letters (1804), and Essay on the Evils of Popular Ignorance (1820), in which he urged the necessity of a national system of education.
He was the eldest son of John Foster, a small farmer, weaver and Baptist, living at Wadsworth Lane in the parish of Halifax, Yorkshire, born 17 September 1770. From a young age he assisted his parents in spinning and weaving wool. At age 17 he became a member of the Baptist congregation at Hebden Bridge; and soon after was "set apart" as minister by a special religious service, and went to reside at Brearley Hall with John Fawcett, who was directing the studies of some Baptist students. After three years here he entered the Baptist College, Bristol, in September 1791, remaining there till May 1792, and then entering on the regular work of a preacher.
Foster first took charge of a small Baptist society at Newcastle-on-Tyne for three months in 1792. In the beginning of 1793 he went to Dublin to minister at a meeting-house in Swift's Alley. He lost his congregation, a recurring feature of his life. He went home, but returned to Dublin in 1795 to take charge of the classical and mathematical school of John Walker, which after eight or nine months he gave up as a failure. He was close to some of the extreme Dublin democrats, exposing him to the danger of imprisonment.
In February 1796 Foster returned once more to Wadsworth Lane, and remained there until early in 1797 he became minister of a general Baptist congregation at Chichester. About midsummer 1799 he removed to the house of an early friend, the Rev. Joseph Hughes, at Battersea, where he spent several months in preaching, and teaching twenty African boys whom Zachary Macaulay was training for mission work. In 1800 he took charge of a small congregation at Downend, near Bristol, and in February 1804 of one at Sheppard's Barton, Frome.