Chapar b. Qaidu (r. c. 702-10/1303-10) was the last ruler of the Mongol Ögödeid ulus (state, people), and great-grandson of Ögödei (r. 1229-41), son and successor of Chinggis Khān. Although Chapar was Qaidu's firstborn son, he was not the one to whom his father intended to bequeath the throne. Unlike the case with the sovereign's other sons, there is no record of Chapar's whereabouts during his father's lifetime. After Qaidu's death, the Chaghatayid khān Duʾa (Duwā, r. 681-706/1282-