Gegeen Khan (Classical Mongolian: Gegegen qaɤan; Khalkha Mongolian: Гэгээн хаан gegeen haan), born Shidibala (from Sanskrit Siddhipāla) and served as Emperor Yingzong of Yuan China, was the ninth grand-khan of the Mongol Empire (Dai-ön Ulus/Yuan Dynasty).

He was the eldest son of Ayurbarwada Buyantu Khan and Radnashiri of the Khunggirad clan. In return for his own crown princeship, Ayurbarwada promised his elder brother Khayishan to appoint Khayishan's son as Crown Prince after his succession. But when Khayishan died, Khayishan's two sons were relegated to borderlands and pro-Khayishan officers were purged. Shidibala's powerful grandmother Dagi installed Shidibala as Crown Prince, and then as Khan, since he was mothered by a Khunggirad khatun.

At that time, the empire was nearly bankrupt due to longtime lax financial policies, but there were little the puppet of Dagi and her retainers could do. Immediately after her grandson's succession, Dagi reinstated Temüder as Minister of the Secretariat and took politics into her own hands more openly than during Ayurbarwada's reign.

In 1322, the deaths of Dagi and Temüder enabled him to seize power. He attempted to drive the Khunggirad faction from the Shidibala-led new administration. He appointed as Minister of the Secretariat Bayiju of the Jalayir, a grandson of Antung and former rival of Temüder. The severe suppression of the powerful faction including the deprivation of Temüder's titles and estabes, the execution of his son drove it into the corner.

In the eighth month of 1323 when he stayed at Nanpo on his way from the summer palace Shangdu to the winter base Dadu, Shidibala, and Bayiju, were assassinated by Temüder's adopted son Tegshi, who attacked Shidibala's Ordo with Asud guards and other soldiers under him. Tegshi asked Yesün Temür to succeed the throne, but Yesün Temür purged Tegshi's faction before he entered Dadu because he feared to become a puppet of it.

His reign was short; his direct rule lasted only for a year after Dagi's death. But he was glorified in Chinese records since he continued Ayurbarwada's protective policies for Chinese cultures. From that point of view, Shidibala's assassination was sometimes explained as the struggle between the pro-Chinese faction and the pro-Mongol faction, for Yesün Temür Khan had ruled Mongolia before succession and his policies appeared unfavorable for Chinese officials.