Liu Ji (died January 18, 646[1]), courtesy name Sidao, was a Chinese politician who served as a chancellor during the reign of Emperor Taizong in the Tang dynasty.
However, around the new year 646, Liu Ji was accused of planning to seize power after Taizong's death, so the emperor ordered him to commit suicide.
Emperor Gaozu of Tang made him the secretary general at Nankang Prefecture (南康州, roughly modern Zhaoqing, Guangdong).
In 641, he was made the deputy imperial censor, when he submitted a petition outlining what he saw as faults by the executive bureau (尚書省, Shangshu Sheng) in avoiding nepotism.
In 639, he was made the deputy head of the examination bureau, and he was given the additional bestowment of Canzhi Zhengshi (參知政事), making him, while not titularly a chancellor, a de facto one.
In 644, Liu Ji submitted a petition stating that doing so was intimidating to the imperial officials, not all of whom were strong with speech and would often be unable to respond.
Emperor Taizong agreed, and from that point on he tried to be even milder in his expressions and words to try to comfort imperial officials stating their suggestions.
While on the way to the frontline, he put Li Zhi in charge at Ding Prefecture (定州, roughly modern Baoding, Hebei), responsible for the logistics behind the lines.
Liu was in charge of exercising de facto authority over the ministries of civil service affairs, ceremonies, and census.
Before Emperor Taizong departed Ding Prefecture, he stated to Liu, "I am going on an expedition, leaving you to assist the Crown Prince.
By the precedents of Yi Yin and Huo Guang, we execute the high level officials who were double-minded, and the state will be secure."