Lionel Cranfield Sackville, 1st Duke of Dorset KG PC (18 January 1688 – 10 October 1765) was an English peer and politician who served as Lord President of the Council from 1745 to 1751.

Perhaps because he had been on a previous diplomatic mission to Hanover, he was chosen to inform George I of his accession to the Crown in August 1714.

George I initially favoured him and numerous offices and honours were given to him: Privy Councillor, Knight of the Garter, Groom of the Stole, Lord Steward, Governor of Dover Castle and Warden of the Cinque Ports.

Dorset, now heavily influenced by his son George Sackville, made the mistake of openly backing the Archbishop.

Even harsh critics admitted his dignity and perfect decorum, a last legacy of the manners of the Court of Queen Anne.