Ruzi Ying 孺子嬰 "Ying the Kid" (r. 6-8 CE), actual name Liu Ying 劉嬰, was an infant emperor and the last ruler of the Former Han period 前漢 (206 BCE-8 CE). He was a great-grandson of Emperor Xuan 漢宣帝 (r. 74-49 BCE) and was enthroned in the age of 2 sui in 6 CE, while the all-powerful regent Wang Mang 王莽 conducted the politics of the empire.
Two years later Wang Mang dethroned Ruzi Ying and proclaimed himself emperor of the Xin dynasty 新 (8-23 CE). Ruzi Ying was given the title of Duke of Ding'an 定安公. In 25 CE, Wang Mang was forced to resign, and the rebel leaders Fang Wang 方望 and Gong Lin 弓林 enthroned Ruzi Ying again as emperor of the Han dynasty. He resided in Linjing 臨涇 (modern Zhenyuan 鎮原, Gansu) but was after a short time defeated by the troops of Liu Xuan 劉玄, who had also adopted the title of emperor (known as the Gengshi Emperor 更始帝, r. 23-25 CE).
The further fate of Ruzi Ying is not known.