Zhongsun Heji 仲孫何忌 or Zhongsun Ji 仲孫忌 (531-481 BCE), posthumous title Meng Yizi 孟懿子, was a high minister in the state of Lu 魯 during the Spring and Autumn period 春秋 (770-5th cent. BCE). He was a member of the family Zhongsun 仲孫 (or Mengsun 孟孫), one of the Three Huan families 三桓 that dominated the state of Lu.
He was a son of Zhongsun Jue 仲孫貜 (Meng Xizi 孟僖子) and served the dukes Zhao 魯昭公 (r. 542-510), Ding 魯定公 (r. 510-495) and Ai 魯哀公 (r. 495-467). Zhongsun Heji appears to have had a twin brother called Nangong Jingshu 南宮敬叔, with whom he was instructed by the philosopher Confucius 孔子.
In 517, the three ducal lateral branches of Zhongsun, Shusun 叔孫 and Jisun 季孫 (the Three Huan families) forced Duke Zhao into exile in Qi 齊. Zhongsun Heji also participated in the feud against the usurpatorious minister Yang Hu 陽虎.
In 510, he visited the court of the king of Zhou in Chengzhou 成周 (modern Luoyang 洛陽, Henan), where a new city was constructed. He also accompanied Duke Ding to Ba 拔 (Tan 郯) where Lu concluded an alliance with the viscount of Zhu 邾.
In 504, he traveled as a diplomat to the state of Jin 晉, together with Jisun Si 季孫斯 (Ji Huanzi 季桓子), and in the same year besieged the town of Yun 鄆, the residence of Yang Hu, but only two years later the mighty potentate was brought down.
In 500, he supported Shusun Zhouchou 叔孫州仇 (Shusun Wushu 叔孫武叔) in the siege of Hou 郈, in a private feud. Somewhat later the Jisun family also suffered from a private quarrel in their town town Fei 費. In the next years he several times attacked the fief of Zhu and occupied some tracts of land to force the viscount of Zhu to acknowledge the dominance of Lu.