Lionel Cranfield Sackville, 1st Duke of Dorset was an English peer and politician who served as Lord President of the Council from 1745 to 1751. He also twice served as Lord Lieutenant of Ireland from 1730 to 1737 and again from 1750 to 1755.

The Lord President of the Council is the presiding officer of the Privy Council of the United Kingdom and the fourth of the Great Officers of State, ranking below the Lord High Treasurer but above the Lord Keeper of the Privy Seal. The Lord President usually attends and is responsible for chairing the meetings of the Privy Council, presenting business for the approval of the Sovereign. In the modern era, the incumbent is by convention always a member of one of the houses of Parliament, and the office is normally a Cabinet position.