Lionel Cranfield Sackville, 1st Duke Of Dorset (January 18, 1688 - October 10, 1765) was an English political leader and Lord Lieutenant of Ireland. Lionel was the son of Charles Sackville, 6th Earl of Dorset and Mary Compton Sackville. He married Elizabeth Colyear, the daughter of General Walter Colyear, in January of 1709. Their sons included Charles, John Philip, and George (1716-1785). Lord Sackville served twice as the King's representative (Lord Lieutenant) in Ireland, from 1731 to 1737 and again in 1751-1755.