Du Yu (Chinese: 杜預; pinyin: Dù Yù) (222–285), courtesy nameYuankai (元凱), was a military general of Cao Wei during the late Three Kingdoms period of Chinese history and a Confucian philosopher of the early Western Jin period (265-316). He came from Duling (杜陵) in the metropolitan region Jingzhao (京兆; near modern Xi'an, Shaanxi) and was married to a daughter of Sima Yi, grandfather of Sima Yan, the first emperor of the Jin Dynasty. Also a prolific author, Du Yu was a self-proclaimed addict of Zuo Zhuan and wrote an influential commentary to it. Du Yu was one of the most important commanders under Zhong Hui during the conquest of the rival state of Shu Han, and he also followed in leading an army in the conquest of Eastern Wu as guardian of the south. Du Yu managed to lay waste to the Eastern Wu army with great force in not the greatest of length of time, and received the surrender of Eastern Wu's last ruler Sun Hao.
Du Yu was also the ancestor of the Tang Dynasty poet Du Fu. Unlike his predecessors, Du Yu used the Zuozhuan to comment the Chunqiu Classic. He therefore combined the two books in one, which has been practice since.