Jayaatu Khan (Classical Mongolian : Jayaɤatu qaɤan; Khalkha Mongolian : Заяат хаан Zayaat haan), born Tugh Temür, was the 11th and 13th grand-khan of the Mongol Empire (Dai-ön Ulus/Yuan Dynasty).

He was the second son of Khayishan Külüg Khan and a Tangut woman. Kuśala Khutughtu Khan was his elder brother. When his father Khayishan suddenly passed away and his younger brother Ayurbarwada inherited khanship in 1311, he and his brother was removed from the central government by his grandmother Dagi and other Khunggirad faction members including Temüder since they were not mothered by Khunggirad khatuns. After Ayurbarwada's son Shidibala Gegeen Khan ascended the throne in 1320, Tugh Temür was relegated to Hainan. When Shidibala was assassinated and Yesün Temür Khan took over as khan, his condition was relaxed. He was given the title of Prince of Huai and was moved to Jiangkang (modern-day Nangjing) and then to Jiangling.

When Yesün Temür Khan died in Shangdu in 1328, Tugh Temür was recalled to Dadu by the Qipchaq commander El Temür since his more influential brother Kuśala stayed in far-away Central Asia. He was installed as grand-khan in Dadu in the 9th month while Yesün Temür's son Ragibagh succeeded to the throne in Shangdu with the support from Yesün Temür's favorite retainer Dawlat Shah . Gaining support from princes and officers in southern Mongolia and Northern China, Dadu-based Tugh Temür eventually won the civil war.

At the same time, however, his elder brother Kuśala gathered support from princes and generals in Mongolia and Chaghatai Ulus and entered Khara Khorum with the overwhelming military presence. Realizing disadvantages, Tugh Temür declared abdication. In the next year, El Temür brought the imperial seal to Kuśala in Mongolia and announced Dadu's intent to welcome him. Kuśala ascended to the throne in the north of Khara Khorum and Tugh Temür became Crown Prince. On his way to Dadu, Kuśala met with Tugh Temür in Ongghuchad near Shangdu in the eight month. Only 4 days after a banquet with Tugh Temür, he suddenly died, or was supposedly killed with poison by El Temür since he feared being lost power to princes and officers of Chaghadai Ulus and Mongolia, who followed Kuśala. Tugh Temür was restored to the throne. El Temür purged pro-Kuśala officers and brought power to warloards.

He was just on a string during his latter three-year reign. Warlords' despotic rule clearly marked the decline of the empire. He is known for cultural contribution instead. He ordered to compile an encyclopaedia named Jingshi Dadian, supported Zhu Xi's Neo-Confucianism and devoted himself in Buddhism. He supervised the construction of the Stupa of Master Zhaozhou in the Buddhist Baolin Temple .

He died in 1332. Although he had a son named El Tegüs , he left a will to make Kuśala's son succeed to the throne. So Kuśala's second son Rinchinbal was installed only at the seventh age.