John Jebb (1736–1786) was an English divine, medical doctor, and religious and political reformer.
He was the son of John Jebb, Dean of Cashel, a member of the Irish branch of a distinguished family which came originally from Mansfield in Nottinghamshire: among his Irish cousins was John Jebb, Bishop of Limerick. He was educated at Peterhouse, Cambridge, where he was elected fellow in 1761, having previously been Second Wrangler at Cambridge in 1757. He was a man of independent judgement, and he and his wife Ann warmly supported the movement of 1771 for abolishing university and clerical subscription to the Thirty-nine Articles. In his lectures on the Greek Testament he is said to have expressed Socinian views. In 1775 he resigned his Suffolk church livings, and two years afterwards graduated M.D. at St Andrews. He practised medicine in London and was elected a fellow of the Royal Society in 1779. He and Ann continued to be involved in political reform.
Like Edmund Law and Francis Blackburne, he was an advocate of soul sleep.