Xu Huang 徐晃 (d. 227), courtesy name Gongming 公明, was a general of the very early years of the Wei dynasty 曹魏 (220-265).
He hailed from Yangyi 楊邑 in the commandery of Hedong 河東 and participated in Yang Feng's 楊奉 suppression campaign against the rebellion of the Yellow Turbans 黃巾起義. For his military successes he was made commandant of cavalry (jiduwei 騎都尉). In 196 he decided to join the warlord Cao Cao 曹操, and participated in the campaigns against Lü Bu 呂布, Liu Bei 劉備 and the tyrant Yuan Shao 袁紹.
During the battle of Guandu 官渡 he destroyed the supplies of Yuan Shao and so critically contributed to his defeat. Xu was rewarded with the title of deputy general (pian jiangjun 偏將軍) and was given the name of a Marquis of Metropolitan Residence (dutinghou 都亭侯). During the battle of Weinan 渭南 Xu Guang secretly passed the Yellow River, attacked the enemy by surprise, and secured the Guanzhong region 關中 for Cao Cao.
Xu Guang was a high officer in the 211 campaign against Ma Chao 馬超 and that against Han Sui 韓遂. Thereafter he assisted Xiahou Yuan 夏侯淵, who was to protect the region of Hanzhong 漢中, which he had just liberated from the Yellow Turban troops under Zhang Lu 張魯. After Yu Jin's 于禁 critical defeat by Guan Yu 關羽 in 219, Xu Huang secured the southwestern border regions to the Sichuan Basin for the house of Cao. With great impetus, Xu liberated Cao Ren's 曹仁 army that was besieged by Guan Yu in Xiangyang 襄陽.
When Cao Cao's son, Cao Pi 曹丕 (known as Emperor Wen 魏文帝, r. 220-226), adopted the title of emperor of Wei, he subsequently gave him the title of General to the Right (you jiangjun 右將軍) and gave him the title of Township Marquis of Luxiang 逯鄉侯, and soon promoted him to Marquis of Yang 楊侯.
During the reign of Emperor Ming 魏明帝 (r. 226-239 CE), Xu Huang was by the regent Sima Yi 司馬懿 entrusted with the defense of Xiangyang against Zhuge Jin 諸葛瑾, a general of the southeastern state of Wu 吳 (222-280). Yet Xu fell ill and died soon. His posthumous title is Marquis Zhuang 楊壯侯.