Emperor Daizong of Tang (January 9, 727 – 23 May 23, 779), personal name Li Yu (name changed in 758 after being created crown prince), né Li Chu, is an emperor of the Chinese Tang Dynasty.

Emperor Daizong is the eldest son of Emperor Suzong – the first Emperor of the Tang dynasty to succeed as the eldest child, and during the Anshi Rebellion (which Emperor Suzong's entire reign is dedicated to fighting), he serves as a general of Tang and Huige joint operations that recapture the capital Chang'an and the eastern capital Luoyang from the rebel state of Yan, and the Anshi Rebellion is finally put down early in his own reign, in 763.

However, thereafter, the Tang state is plagued by warlordism, with such generals as Tian Chengsi, Li Baochen, and Liang Chongyi effectively ruling their realms as independent states, only nominally loyal to Emperor Daizong.

This would prove disastrous for future generations as future Tang emperors would be unable to remove or control these warlords and the central government's power would thus be slowly eroded and diminished.

The power of the warlords would not prevent the Tang western territories from being overrun by Tibetan forces and eventually lost to Tibet, with the Tibetan forces even capturing Chang'an, in 763, although being expelled shortly after.

Emperor Daizong is credited for removing the corrupt eunuch Li Fuguo, who had placed him on the throne, from power, but the rest of Emperor Daizong's reign will also see dominance by such individuals as the eunuchs Cheng Yuanzhen and Yu Chao'en, as well as the chancellor Yuan Zai.

It is also worth noting that Emperor Daizong became the first Tang emperor to succeed to the throne as a result of maneuvers by eunuchs.

Emperor Daizong is himself also said to be overly devout in Buddhism.