'Ali Khalil (Chagatai and Persian: علی خلیل), also known as Ali-Sultan (Chagatai and Persian: علی سلطان), was the khan (r.1339-1342) of the Chagatai Khanate. He was a descendant of Qadan, son of the second Great Khan Ögedei. 'Ali attacked the ordo (palace) of Yesun Temur and usurped the throne. He was the first and last one who had restored the Ögedeid authority over the Chagatai Khanate since the reigns of Kaidu and his son Chapar. During his reign, Islam fully absorbed the Chagatai Mongols and 'Ali persecuted followers of other religions. He is the one who ordered the killing of six Franciscan friars at Almalik in 1339, as depicted in The Martyrdom of the Franciscans, by Ambrogio Lorenzetti.