John Moore was born in 1646 in the Leicestershire village of Sutton, his father an ironmonger and his ancestors the middling De La Moore family of Devon from whom he took his coat of arms. He was educated at the grammar school in Market Harborough then went up to Clare Hall in Cambridge, taking his MA in 1669, and was elected a fellow of the college. His great interest in medicine did not, contrary to some contemporary reports, lead him to earn a degree of M.D., but he was awarded a D.D. from Oxford in 1673 and from Cambridge in 1681. From 1670 he served as private chaplain to Heneage Finch, later Lord Chancellor, and this service in the royal circle first saw fruit in his appointment by the King to the Rectory of Blaby in Leicestershire where he servied until 1687. His move to London came in 1687 when he was appointed rector of St Augustine, Watling Street, which he served for just two years; in 1689 King William and Queen Mary appointed him rector of the wealthy parish of St Andrew’s Holborn, where he served as royal Chaplain-in-Ordinary.
In 1691 he was consecrated Bishop of Norwich, in which location he began to build his library in earnest. In 1707 he was translated to the bishopric of Ely, and moved to Ely Place in London, the long-standing home of the Bishops of Ely. There he continued to expand his library, and to invite visitors to use it and borrow books. This position brought with it the Visitorship of Trinity College, Cambridge, in which capacity he was serving in the trial of Richard Bentley, Master of the college, when he caught the chill that ultimately led to his death on 31 July 1714. He was married twice, firstly in 1679 to Rose Butler of Barnwell Priory, Cambridgeshire, with whom he had three sons and three daughters. After Rose’s death in 1689 he married Dorothy, widow of Sir Richard Browne, and had three more sons.