Li Yuansu (李元素) (died October 26, 696[1]) was an official of Wu Zetian's Zhou dynasty, serving twice as chancellor.
He was, at one point, the magistrate of Wude County (武德, in modern Jiaozuo, Henan), when his superior, Li Wenjian (李文暕) the prefect of Huai Prefecture (roughly modern Jiaozuo) was set to collect gold and silver from the people to make barrels to offer to the emperor, and the people resented it.
As of 692, during Wu Zetian's reign, Li Yuansu was acting deputy minister of treasury (地官侍郎, Diguan Shilang), when she promoted him to be Wenchang You Cheng (文昌右丞), one of the secretaries general of the executive bureau of government (文昌臺, Wenchang Tai) and gave him the designation Tong Fengge Luantai Pingzhangshi (同鳳閣鸞臺平章事), making him a chancellor de facto.
Just slightly more than a month later, however, he, along with other chancellors Li Youdao, Wang Xuan, Yuan Zhihong, and Cui Shenji, and other officials Kong Siyuan (孔思元), and Ren Linghui (任令輝), were falsely accused of crimes by Wu Zetian's secret police official Wang Hongyi.
By 694, however, Li Yuansu had been recalled from exile and was serving as Wenchang You Cheng again, when he was made Fengge Shilang (鳳閣侍郎), the deputy head of the legislative bureau, and again given the de facto chancellor designation of Tong Fengge Luantai Pingzhangshi.