Abu al-Hasan 'Ali (died c. 1009) was Khwarazm-Shah from 997 until his death. The second member of the Ma'munid dynasty, he was the son of Mamun I.
In 997 Ali took over Khwarazm following his father's death. Little is known of his reign. He married the Ghaznavid sultan Mahmud's sister Kah-Kalji, but also was in close contact with the Ghaznavids' rivals, the Karakhanids. He died sometime around 1009 and was succeeded by his brother, Abu al-Abbas Mamun.
"'Ali b. Ma'mun." Encyclopædia Iranica. 17 August 2006.