The Kingdom of Mangalai (Chinese: 曼尕賴; pinyin: Màngǎlài), also called Mangalai Suyah, was a 13th-century kingdom with its capital in East Turkistan's Aksu city. Mentioned by Marco Polo, it was subservient to Genghis Khan from 1224 to his death in 1227. On the edge of the Yuan dynasty, Mangalai was controlled by the Chagatai Khanate. Its latter history sees periods of autonomy or inclusion of one of many larger kingdoms including: Mogulistan, Kashgar, and Kingdom of Kashgaria. In 1877 the area came under the control of the Qing dynasty and remains part of the Chinese autonomous region of Xinjiang.

The territory of Mangalai was described as bound on the east by Bügür and Kucha; to the west by the Kingdom of Fergana; to the north by Issigh-Kul; and to the south by the Yugurs.^[1]

Mangalai Suyah was given to Urtubu by Chagatai Khan, the grandfather of Amir Bulaji.^[1]