Isabel de Warenne, Countess of Arundel (c. 1228 – 23 November 1282) was an English peer. She was widowed when she was about 17 years old, with a large estate, upon which she founded a Cistercian order convent, England's only convent to be Cistercian at the time of its founding. In 1252, she rebuked King Henry III for not paying her money she was owed.