Niu Sengru (牛僧孺) (780 – January 27, 849), courtesy name Si'an (思黯), formally Duke Wenzhen of Qizhang (奇章文貞公), was Chinese historian, military general, and politician of the Tang Dynasty, serving as a chancellor during the reigns of Emperor Muzong and his sons Emperor Jingzong and Emperor Wenzong. He was commonly regarded as the leader of one of the two court factions at the time — the faction later known as the Niu Faction — during the Niu-Li Factional Struggles.