Yixin, better known in English as Prince Kung or Gong, was an imperial prince of the Aisin Gioro clan and an important statesman of the Manchu-led Qing dynasty in China. He was a regent of the empire from 1861 to 1865 and wielded great influence at other times as well.

The House of Aisin-Gioro was a Manchu clan that ruled the Later Jin dynasty (1616–1636), the Qing dynasty (1636–1912), and Manchukuo (1932–1945) in the history of China. Under the Ming dynasty, members of the Aisin Gioro clan served as chiefs of the Jianzhou Jurchens, one of the three major Jurchen tribes at this time. Qing bannermen passed through the gates of the Great Wall in 1644, and eventually conquered the short-lived Shun dynasty, Xi dynasty and Southern Ming dynasty. After gaining total control of China proper, the Qing dynasty later expanded into other adjacent regions, including Xinjiang, Tibet, Outer Mongolia, and Taiwan. The dynasty reached its zenith during the High Qing era and under the Qianlong Emperor, who reigned from 1735 to 1796. This reign was followed by a century of gradual decline.