Ligdan (died 1634, Tibet) was the last of the paramount Mongol khans (ruled 1604–34).
Ligdan was a member of the Chahar royal family in which the Mongol supreme khanate was vested. He lived at a time when the Mongols were abandoning their traditional shamanism to convert to Tibetan Buddhism. He had Buddhist temples constructed and religious texts translated from Tibetan into Mongolian.
Ligdan’s authority as khan was not recognized beyond his own tribe, and his attempts to maintain a degree of control over nearby Mongols were ignored. He was known as a formidable fighter, however, and was feared by his neighbours. Attacks from enemy Mongol tribes and clans and from the Manchus who were coming to power in China forced him and many of the Chahars to flee westward. Ligdan died before he could reconsolidate his position, and the Chahar line ended.