William Cavendish, 3rd Duke of Devonshire, was a British nobleman and Whig politician who sat in the House of Commons from 1721 to 1729 when he inherited the Dukedom.

William Cavendish, 2nd Duke of Devonshire was a British nobleman and politician. He was the eldest son of William Cavendish, 1st Duke of Devonshire and Lady Mary Butler. A prominent Whig, he was sworn of the Privy Council in 1707, and served as Lord President of the Council from 1716 to 1718 and 1725 to 1729.