Sir John Willes PC KC (29 November 1685 – 15 December 1761) was an English lawyer and judge who was the longest-serving Chief Justice of the Court of Common Pleas since the 15th century. He was also a Member of Parliament.
He was born at Bishop's Itchington in Warwickshire; his father, the Reverend John Willes, vicar of the parish, was a younger son of the long-established Willes family of Newbold Comyn. Dr. Edward Willes, Bishop of Bath and Wells, was his brother. Their mother was Anne (or Mary) Walker, daughter of Sir William Walker, who was three times Mayor of Oxford between 1674 and 1685.
Willes was educated at Lichfield Grammar School and Trinity College, Oxford, and was also elected a fellow of All Souls. While he was a student at Oxford he got into serious trouble for publishing pamphlets about the Government which were arguably seditious, and was threatened with prosecution as a result. His career was saved by the intervention of John Carteret, 2nd Earl Granville, who pleaded for clemency. Granville often said in later years that he had made Willes a judge by saving him from the pillory. Willes joined Lincoln's Inn, and was called to the bar in 1713; in 1719 he became a King's Counsel, and in 1726 he was appointed a judge on the Chester circuit.