Liu Jin (simplified Chinese: 刘瑾; traditional Chinese: 劉瑾; pinyin: Liú Jǐn; Wade–Giles: Liu Chin; 28 February 1451 – 25 August 1510) was a powerful Ming dynasty Chinese eunuch during the reign of the Zhengde Emperor.
Liu was famous for being one of the most influential officials in Chinese history. For some time, Liu was the emperor in all but name. He was the leader of the "Eight Tigers", a powerful group of eunuchs who controlled the imperial court. Liu was from the area of Xingping, a county in Shaanxi province, approximately 30 miles west of Xi'an prefecture.
Liu Jin's original surname was Tan (談). When he became a eunuch under the aegis of a eunuch official named Liu, he changed his surname to Liu.