He was born at Clapham to the south-west of central London, while his father Henry Venn was curate there, on 9 March 1759. He entered Sidney Sussex College, Cambridge, graduated B.A. in 1781, and M.A. in 1784. Venn was rector of Little Dunham, Norfolk, from 1783 to 1792, and rector of Clapham from 1792 to his death. He was one of the original founders of the Church Missionary Society in 1797, and was a leading abolitionist and philanthropist. These evangelistic and humanitarian interests brought him into close association with abolitionists such as William Wilberforce and Granville Sharp. He ran the school set up by the Society for the Education of Africans which was set up in Clapham in 1799. He died at Clapham on 1 July 1813. A volume of his sermons was published after his death. Some of his friends arranged for the following memorial plaque to be erected on the north side of the church in Clapham: "To the memory of the Reverend John Venn, M.A. for twenty years Rector of this parish. He was the son of the Reverend Henry Venn, Vicar of Yelling; and his progenitors, for several generations, were Ministers of the Church of England. He was endowed by providence with a sound and powerful understanding: and he added to an ample fund of classical knowledge a familiar acquaintance with all the more useful parts of philosophy and science: His taste was simple. His disposition was humble and benevolent. His manners were mild and conciliating. As a Divine, he was comprehensive and elevated in his views, and peculiarly conversant with Theological subjects; but he derived his chief knowledge from the scriptures themselves, which he diligently studied and faithfully interpreted. As a Preacher, he was affectionate and persuasive, intellectual and discriminating, serious, solemn, and devout; anxious to impress on others those evangelical truths which he himself so deeply felt. By his Family, among whom he was singularly beloved, his remembrance will be cherished with peculiar tenderness. Having been sustained, during a long and trying illness, by a stedfast faith in that Saviour whom in all his preaching he laboured to exalt, he died 1 July 1813, aged 54 years, leaving to his surviving family and flock an encouraging example of the blessedness of those who embrace with their whole hearts the religion of Jesus Christ."