Robert Burnell (died October 25, 1292) was an English bishop who served as Lord Chancellor of England in the years 1274-1292.
He was born at Acton Burnell in Shropshire, and probably began his public life as a clerk in the royal chancery. He was soon in the service of Edward, the eldest son of King Henry III, and was constantly in attendance on the prince, whose complete confidence he appears to have enjoyed. Having received some ecclesiastical preferments, he acted as one of the regents of the kingdom from the death of Henry III in November 1272 until August 1274, when the new king, Edward I, returned from Palestine and made him his chancellor.
In 1275 Burnell was elected Bishop of Bath and Wells, and three years later Edward repeated the attempt which he had made in 1270 to secure the archbishopric of Canterbury for his favourite. The bishop's second failure to obtain this dignity was probably due to the unacceptability of his lifestyle, which also partly accounts for the hostility between himself and his victorious rival, Archbishop Thomas Peckham.
As the chief adviser of Edward I during the earlier part of his reign, and as a trained and able lawyer, the bishop took a prominent part in the legislative acts of the "English Justinian," whose activity, in this direction coincides with Burnell's tenure of the office of chancellor. The bishop also influenced the king's policy with regard to France, Scotland and Wales; was frequently employed on business of the highest moment; and was the royal mouthpiece on several important occasions. In 1283 a council resembling a parliament met in his house at Acton Burnell, and he was responsible for the settlement of the court of chancery in London. In spite of his numerous engagements, Burnell found time to aggrandize his bishopric, to provide liberally for his nephews and other kinsmen, and to pursue his cherished but futile aim of founding a great family. He amassed great wealth; and on his death he left numerous estates in Shropshire, Worcestershire, Somerset, Kent, Surrey and elsewhere.