Sir John Lenthall (c. 1625–1681) was an English Member of Parliament. He was elected MP for Gloucester in 1645, knighted by Oliver Cromwell in 1658 and made Governor of Windsor Castle from 1657 to 1660. After the 1660 Restoration of the Monarchy he was pricked Sheriff of Oxfordshire for 1672–73 and knighted a second time by Charles II in 1677.