Zhao Xi (simplified Chinese: 赵憙; traditional Chinese: 趙憙; pinyin: Zhào Xǐ; 4-80 CE), courtesy name Boyang (simplified Chinese: 伯阳; traditional Chinese: 伯陽; pinyin: Bóyáng), was a politician who lived in the early Eastern Han Dynasty.
Zhao Xi was born in Wan, Nanyang Commandery (present-day Nanyang, Henan). At a young age, he was known for his integrity. When Zhao Xi was 15, his elder cousin, who had no son, was murdered. Zhao Xi harboured the thought of avenging his cousin, so he brought a group of people with him to confront his cousin's killer. The murderer was ill, and Zhao Xi felt that it was inhumane to kill him at that time, so he spared him. When the killer had recovered, he bound himself and came to plead with Zhao Xi. However, Zhao Xi refused to meet him and had him killed.
In 9 CE, Wang Mang usurped the throne of the Western Han Dynasty and declared himself emperor of the Xin Dynasty. By 23 CE, several revolts had broken out throughout China due to Wang Mang's incompetent rule. Around the time, Liu Xuan, a descendant of the Han imperial clan, was proclaimed "Emperor Gengshi" by rebels aiming to restore the Han Dynasty. Gengshi's forces were attacking Wuyin (舞陰), a city controlled by a certain Li family. Gengshi heard that Zhao Xi had some influence over the Li family, so he invited Zhao to help him persuade the Lis to surrender. When Gengshi met Zhao Xi, he saw that the latter was merely a youth, so he viewed Zhao Xi lightly. When Zhao Xi arrived in Wuyin, the Li family surrendered on their own accord, and Emperor Gengshi granted Zhao Xi the title of "Lieutenant General of Five Mights" (五威偏將軍) for his achievement.