Hou Junji (died April 29, 643[1]) was a Chinese general and official who served as a chancellor during the reign of Emperor Taizong in the Tang dynasty.

Late In 626, when Emperor Taizong personally ranked the contributions of the generals and officials in order to grant them fiefs, Emperor Taizong ranked five of them—Hou Junji, Zhangsun Wuji, Fang Xuanling, Du Ruhui, and Yuchi Gong to be contributors of the highest grade, and Hou was created the Duke of Lu.

In 630, Emperor Taizong made Hou the minister of defense and gave him the additional designation of Canyi Chaozheng (參議朝政), making him a de facto chancellor.

Most Tang generals wanted to withdraw, but Hou advocated continued advance, and Li Jing agreed, eventually allowing complete victory, as Murong Fuyun was killed by his subordinates, allowing his son Murong Shun, whom Tang supported, to become khan (as Yidou Khan).

In 637, as part of Emperor Taizong's scheme to bestow prefectures on his relatives and great generals and officials as their permanent domains, Hou's title was changed to Duke of Chen, and he was given the post of prefect of Chen Prefecture (陳州, roughly modern Zhoukou, Henan), to be inherited by his heirs.

Soon, however, with many objections to the system, the strongest of which came from Zhangsun Wuji, Emperor Taizong cancelled the scheme, although Hou's title remained Duke of Chen.

Emperor Taizong sent Hou to counterattack, assisted by other generals Zhishi Sili (執失思力), Niu Jinda (牛進達), and Liu Jian (劉簡).

(This time, Emperor Taizong agreed, sending Princess Wencheng, a daughter of a clansman, to marry Songtsen Gampo.)

Around the new year of 640, Qu Wentai (麴文泰), the king of Gaochang, formed an alliance with Western Tujues who are hostile to Tang.

Emperor Taizong, when he found out about these events, put Hou and some of his generals under arrest less than 10 days after their return to Chang'an.

Hou responded, "I conquered a kingdom, but I ran into someone throwing a temper tantrum big enough to overturn a house.

Li Chengqian therefore gathered a group of political and military officials around him to consider overthrowing his father, including his uncle Li Yuanchang (李元昌) the Prince of Han, his cousin Zhao Jie (趙節), and brother-in-law Du He (杜荷, Du Ruhui's son).

But as I destroyed two kingdoms as a general, please speak for me to His Imperial Majesty to request that I could have a son remaining to carry on the lineage, on the basis of my accomplishments."

Emperor Taizong, when he heard this, pardoned Hou's wife and children but exiled them to the modern Guangdong region, and confiscated his properties.

At one point, Li Daozong also spoke to Emperor Taizong, stating, "Hou Junji has too much ambition and too little talent.