William Elstob (1673–1715), was an English divine.
Elstob was the son of Ralph Elstob, merchant of Newcastle-upon-Tyne, and was baptised at All Saints' Church, Newcastle, on 1 January 1673. The Elstob family claimed descent from ancient Welsh kings, and had long been settled in the diocese of Durham. Elstob was educated in Newcastle and at Eton. At the age of sixteen - on the advice of his uncle and guardian, Charles Elstob, D.D., prebendary of Canterbury from 1685 to 1721 - he was sent to Catharine Hall, Cambridge, 'in a station below his birth and fortune.' His health also suffered when at Catherine Hall, and so he left for Queen's College, Oxford, where he entered as a commoner and graduated B.A. in 1694. He was elected fellow of University College, Oxford on 23 July 1696, and took his M.A. degree on 8 June 1697. Hearne says that having failed of election to All Souls as a south country man, he 'became a northern man,' and was elected one of Skirlaw's fellows at University College. In 1702 he was presented by the dean and chapter of Canterbury, presumably through his uncle's influence, to the united parishes of St. Swithin and St. Mary Bothaw, London. Here he died, after a lingering illness, on 3 March 1714-15, and was buried in the chancel of St. Swithin's. He was chaplain to Bishop Nicolson of Carlisle, who in February 1713 applied for Chief Justice Parker's influence for his appointment to the preachership at Lincoln's inn.