Emperor Zhongzong of Tang (26 November 656 – 3 July 710), personal name Lǐ Xiǎn, at times during his life Li Zhe and Wu Xian, is the fourth Emperor of the Tang Dynasty of China, ruling briefly in 684 and again from 705 to 710.

Emperor Zhongzong is the son of Emperor Gaozong of Tang and Empress Wu (later known as Wu Zetian).

He succeeds his father in 684.

His mother, however, deposes him less than two months later in favor of his younger brother Emperor Ruizong.

The former emperor, demoted to a princely rank, is sent in exile in the provinces and placed under house arrest.

Six years later, Emperor Ruizong in turn relinquishes the throne to his mother and Empress Dowager Wu officially proclaims herself "Emperor", while Emperor Ruizong is made crown prince.

By 698, the court is caught in the middle of a bitter power struggle.

In an attempt to decrease the power struggle, Empress Wu liberates the former emperor from his 14 years of seclusion and recalls him to the capital in April 698.

He is reinstated as crown prince in October 698, taking the place of his brother.

On 20 February 705, a palace coup deposes Wu Zetian and Emperor Zhongzong is restored as emperor three days later.

Emperor Zhongzong reigns for five years but is a rather weak and easily influenced ruler.

Real power is in the hands of his empress consort, Empress Wei and her lover Wu Sansi (Wu Zetian's nephew).

In 710, Emperor Zhongzong dies, allegedly poisoned by Empress Wei, who then installs his son, Li Chongmao, as emperor.

Empress Wei, who had failed to install her daughter Li Guo'er, the Princess Anle, as heir to Emperor Zhongzong, thinks that Li Chongmao, born of Zhongzong and a concubine and who is only 16 years old, will be easy to control and allow her to preserve her power.

The scheme fails, however, when Princess Taiping, the sister of Emperor Zhongzong, launches a coup two weeks later with her nephew Li Longji (later Emperor Xuanzong), son of the abdicated Emperor Ruizong, and overthrows Empress Wei and the young emperor.

Emperor Ruizong, the father of Li Longji and the older brother of Princess Taiping, is restored as emperor.