Su Weidao (Chinese: 蘇味道; 648?-705?), was an official of the Chinese Tang dynasty and Wu Zetian's Zhou dynasty, twice serving as chancellor during Wu Zetian's reign.
Su Weidao might have been born in 648, at the end of the reign of Emperor Taizong. His family was from Zhao Prefecture (趙州, roughly modern Shijiazhuang, Hebei). In his youth, he was well known in the locale for his literary talent, along with Li Jiao, also from Zhao Prefecture. After he passed the imperial examination, he was made the sheriff of Xianyang County (咸陽, in modern Xianyang, Shaanxi). Pei Xingjian (裴行儉), then the deputy minister of civil service affairs, was impressed by his talent, and in 679, when Pei was set to command an army against Western Tujue's Shixing Khan Ashina Duzhi (阿史那都支), who had just rebelled against Tang Dynasty, Pei invited Su to serve as his secretary. Around that time, the official Pei Judao had just been made a general commanding the imperial guards, and, after searching for a talented person to write a thanksgiving submission to then-reigning Emperor Gaozong (Emperor Taizong's son), found Su. The submission that Su wrote on Pei Judao's behalf was said to be well-written in an intricate manner, and he became famous.
In 694, during the reign of Emperor Gaozong's wife Wu Zetian, Su Weidao was serving as Fengge Sheren (鳳閣舍人), a mid-level official at the legislative bureau of government (鳳閣, Fengge), when he was promoted to be the deputy head of the legislative bureau (鳳閣侍郎, Fengge Shilang) and given the designation Tong Fengge Luantai Pingzhangshi (同鳳閣鸞臺平章事), making him a chancellor de facto. Soon thereafter, when Wu Zetian's lover Huaiyi was commissioned to command an army against Eastern Tujue, Su and fellow chancellor Li Zhaode were commissioned to assist Huaiyi. In late 694, Wu Zetian, displeased with the power Li had, exiled Li, and fellow chancellor Zhou Yunyuan and the assistant chief judge of the supreme court, Huangfu Wenbei (皇甫文備), then submitted articles of impeachment against Su and several fellow chancellors -- Doulu Qinwang, Wei Juyuan, Du Jingjian, and Lu Yuanfang—for not being able to curb Li Zhaode's power. The five chancellors so accused were all demoted to be prefectural prefect—in Su's case, to be the prefect of Ji Prefecture (集州, roughly modern Bazhong, Sichuan).