Yahya ibn Ismail al-Mamun (Arabic: المأمون بن ذي النون) (died 1075) was the second ruler of the Berber Hawwara Dhulnunid dynasty who was king of the Taifa of Toledo between 1043 and 1075.[1]
Yahya ibn Ismail succeeded his father Ismaïl ibn Dhi 'l-Nun in 1043. He died at Córdoba in 1075.