Sir Ralph Sadler or Sadleir PC, Knight banneret 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.

In the Kingdom of England, the title of Secretary of State came into being near the end of the reign of Elizabeth I, the usual title before that having been King's Clerk, King's Secretary, or Principal Secretary.