Xi Zuochi (after 316–384), courtesy name Yanwei, was a Jin dynasty historian native to Xiangyang, Hubei. He is principally remembered for being the first historian to regard the Wei dynasty as an illegitimate successor to the Han dynasty.
Born into a powerful family of local magnates, Xi Zuochi was ambitious and studious from a young age. Beginning his career as a clerk, Xi Zuochi came to the attention of Inspector of Jing Province Huan Wen through the repeated recommendations of Yuan Qiao (袁喬), magistrate of Jiangxia commandery. Huan Wen greatly esteemed Xi Zuochi, promoting him three times during the course of a single year, such that Xi Zuochi held the position of Superintendent of Records in the central administration of Jing Province while he was still a young man, possibly not yet thirty years old. Huan Wen would occasionally employ Xi Zuochi as an administrative aide whilst on campaign, and he excelled in all his duties whether in camp or in the office.
Xi Zuochi's relationship with his employer became strained after a visit to the capital city, where he met Sima Yu, future Emperor Jianwen of Jin and political rival of Huan Wen. Xi Zuochi was apparently so taken with Sima Yu that Huan Wen felt it best to distance himself from Xi Zuochi, and demoted him to Grand Administrator of Hengyang, in the Xiang river basin far to the south, in present-day Hunan. Xi Zuochi may have suffered a stroke at this time, contributing to his difficulty walking later in life.