Sir Ralph Sadler or Sadleir PC, Knight banneret (1507 – 30 March 1587) was an English statesman, who served Henry VIII as Privy Councillor, Secretary of State and ambassador to Scotland. Sadler went on to serve Edward VI. Having signed the device settling the crown on Jane Grey in 1553, he was obliged to retire to his estates during the reign of Mary I. Sadler was restored to royal favour during the reign of Elizabeth I, serving as a Privy Councillor and once again participating in Anglo-Scottish diplomacy. He was appointed Chancellor of the Duchy of Lancaster in May 1568.