Mabel FitzRobert, Countess of Gloucester (1090 – 29 September 1157) was an Anglo-Norman noblewoman, and a wealthy heiress who brought the lordship of Gloucester, among other prestigious honours to her husband, Robert, 1st Earl of Gloucester upon their marriage. He was the illegitimate son of King Henry I of England. Her father was Robert Fitzhamon, Lord of Gloucester and Glamorgan.