Emperor Xuānzong of Tang, Chinese emperor (b. 810)
Emperor Xuanzong of Tang (July 27, 810 – September 7, 859) (reigned April 25, 846 – September 7, 859) was an emperor in the latter part of the Tang dynasty of China. Personally named Li Yi, later renamed Li Chen (Chinese: 李忱), and known before his reign as the Prince of Guang, he was considered the last capable emperor of Tang China. Succeeding emperors after Xuanzong would either be too young or be dominated by eunuchs or warlords. Emperor Xuanzong was the 13th son of Emperor Xianzong (r. 806–820) and an uncle of the previous three emperors, Emperor Jingzong, Emperor Wenzong, and Emperor Wuzong.

To distinguish Emperor Xuanzong from his ancestor Emperor Xuánzong (personal name Li Longji), as their temple names are rendered identically in Wade–Giles and when pinyin tonal marks are not used, Xuanzong is occasionally referred to as Xuanzong II in western sources; in Chinese, however, their temple names (宣宗 for him and 玄宗 for Li Longji) are clearly distinct and this device is not used.