Sir William Weston (c. 1470 – 7 May 1540) was the last Prior of the Order of Knights of the Hospital of Saint John of Jerusalem in England before the Dissolution of the Monasteries, during the reign of King Henry VIII. As such he ranked as Premier Baron in the roll of peers. He is characterised as one of the influential adherents of the papacy. His cadaver effigy survives in the crypt of the Priory Church of St John, Clerkenwell in Middlesex (now in central London), the former headquarters of the Order.