Tolui, (Classic Mongolian: Toluy, Tului, , , Tolui Khan (meaning the Khan Tolui)) (1192–1232) was the fourth son of Genghis Khan by his chief khatun Börte. His ulus, or territorial inheritance, at his father's death in 1227 was the homelands in Mongolia, and it was he who served as civil administrator in the time it took to confirm Ögedei as second Great Khan of the Mongol Empire (1206–1368). Before that he had served with distinction in the campaigns against the Jin dynasty, the Western Xia and the Khwarezmid Empire, where he was instrumental in the capture and massacre at Merv and Nishapur. He is a direct ancestor of most of the Emperors of Mongolia and the Ilkhanids.
Tolui never used the title of Khagan himself; though neither Genghis Khan nor his immediate three successors ever use any reigning titles unlike the neighboring Chinese dynasties in the south. Tolui was awarded the title of Khagan by his son Möngke and was given a temple name (Chinese: 元睿宗; pinyin: Yuán Ruìzōng; Wade–Giles: Jui-Tsung) by his other son Kublai, when he established the Yuan dynasty a few decades later.