Zhangsun Wuji (died 659),
courtesy name Fuji, formally the
Duke of Zhao , was a Chinese official who served as a
chancellor in the early
Tang dynasty. He was
Empress Zhangsun's brother, which made him a brother-in-law of
Emperor Taizong (Li Shimin) and a maternal uncle of
Emperor Gaozong (Li Zhi). He was an important advisor to Li Shimin when the latter was still the Prince of Qin during the reign of his father,
Emperor Gaozu. He helped Li Shimin overcome his brothers
Li Jiancheng (the Crown Prince) and
Li Yuanji (the Prince of Qi) in a succession struggle at the
Xuanwu Gate Incident, eventually enabling Li Shimin to become the heir apparent and later the emperor. He was also instrumental in Emperor Taizong's selection of Li Zhi as the Crown Prince, and was exceedingly powerful after Li Zhi took the throne as Emperor Gaozong. However, he gradually fell out of his nephew's favour by failing to support Emperor Gaozong's decision to depose his first wife,
Empress Wang, and replacing her with
Empress Wu. In 659, Zhangsun Wuji was falsely accused of treason by Empress Wu's political ally,
Xu Jingzong, and eventually ordered to be sent into exile by Emperor Gaozong. Xu Jingzong subsequently sent the official Yuan Gongyu (袁公瑜) to force Zhangsun Wuji to commit suicide on his way to exile.