Huan Yi 桓齮 was a general of the state of Qin 秦 in the late Warring States period 戰國 (5th cent.-221 BCE). General Pang Nuan 龐煖 of Zhao 趙 occupied in 236 several towns of the state of Yan 燕, whereupon Yan asked the state of Qin for help. Huan Yi, Yang Duan 楊端, and Wang Jian 王翦 commanded the relief campaign against Zhao and took its towns Ye 鄴 (today's Linzhang 臨漳, Hebei) and Anyang 安陽 (Hebei), as well as Eyu 閼與 (Heshun 和順, Shanxi), and Liaoyang 撩陽 (Zuoquan 左權, Shanxi).
In 234, Huan Yi attacked Pingyang 平陽 (Linfen 臨汾, Shanxi) and Wucheng 武城 (Cixian 磁縣, Hebei), killed general Hu Zhe 扈輒 and massacred 100,000 troops of Zhao. He then left Shangdang 上黨, passed the Taihang Ridge 太行山 and invaded Zhao by taking Chili 赤麗 and Yi'an 宜安 (Gaocheng 槀城, Hebei). Zhao thereupon laid the supreme command in the hands of Li Mu 李牧, who defeated Huan Yi in the battle of Fei 肥 (Jinxian 晉縣, Hebei) and pushed him back out of Zhao. Huan Yi's way back was cut off, and he had to flee to Yan in the northeast. It was the last great victory of Zhao over Qin.