Cao Zhi, courtesy name Yungong (允恭), posthumously known as Duke Ding of Juancheng (鄄城定公), was a son of Cao Zhi, Prince Si of Chen, and his unnamed concubine, and a grandson of Cao Cao. Besides his heritage, Cao Zhi was best known for his friendship with Sima Yan, and his support of Sima You remaining in the capital to help in the administration of the empire, against Yan's wishes.