The title of Baron Grey of Codnor is a title in the peerage of England.
This barony was called out of abeyance in 1989, after 493 years, in favour of the Cornwall-Legh family of East Hall, High Legh, Cheshire. Since the death of the 10th and last Earl of Stamford (seated at neighbouring Dunham Massey) in 1976, the Lords Grey of Codnor are senior lineal representatives of the noble house of Grey, and as hereditary peers are eligible for election to a seat in the House of Lords.
This branch of the ancient Grey family was in the Middle Ages at Codnor Castle. Together with the other noble branches of the Greys, they share descent from the Norman knight Anchetil de Greye, a vassal of King William I. During the reign of King John, Sir Henry de Grey purchased the manor of Grays Thurrock in Essex from Isaac the Jew and his son Josce, confirmed by the king in 1195. Sir Henry de Grey also held the manor of Codnor, Derbyshire, granted by the boy King Henry III's regents as well as the manor of Grimston, Nottinghamshire; he married Isolda, daughter of Sir Hugh Bardolf by his wife Isabel née Twist. Sir Henry died a few years later in 1219, and his widow married again to Sir Reynold de Bohun.