Jeffery, John an English theologian, was born at Ipswich in 1647. He studied at Catharine Hall, Cambridge, entered the Church, and was appointed rector of Dennington, Suffolk; then of a parish in Norwich. His exemplary conduct, sound teachings, and great erudition rendered him very popular. In 1687 he obtained the livings of Kirton and Falkenham, and in 1694, Tillotson, with whom he was intimately acquainted, made him archdeacon of Norwich. He died in 1720. Jeffery was much opposed to religious controversies, holding that they generated "more heat than light." He published Sir Thomas Browne's Christian Morals; Moral and Religious Aphorisms, taken from Dr. Wicheote's papers. A complete collection of his own Sermons and Tracts was published (London, 1753, 2 vols. 8vo). See Memoirs prefixed to the collection; Hoefer, Nouv. Biog. Géneralé, 26:632; Allibone, Dictionary of Authors, i, 959.