Wang Gui (571–639), courtesy name Shujie, posthumously known as Duke Yi of Yongning, was a Chinese official who served as a chancellor during the reign of Emperor Taizong (Li Shimin) in the Tang dynasty. He had previously served Li Shimin's elder brother, Li Jiancheng, with whom Li Shimin was locked in an intense rivalry during the reign of their father, Emperor Gaozu, but after Li Shimin killed Li Jiancheng and then took the throne, he knew that Wang was faithful to Li Jiancheng and was capable, and therefore retained him, eventually making him chancellor. Wang was known for his honest and blunt criticism of the emperor, and for that was honored by Taizong, who appreciated such criticism.