Charles Spencer, 3rd Earl of Sunderland, KG, PC (23 April 1675 – 19 April 1722), styled as Lord Spencer from 1688 to 1702, was a British politician from the Spencer family. He served as Lord Lieutenant of Ireland (1714–1717), Lord Privy Seal (1715–1716), Lord President of the Council (1718–1719) and First Lord of the Treasury (1718–1721). He is an ancestor of both Winston Churchill and Diana, Princess of Wales, and through her, the current heir to the British throne, William, Prince of Wales.