Chen Yixing (陳夷行) (died 844), courtesy name Zhoudao (周道), was an official of the Chinese dynasty Tang Dynasty, serving twice as a chancellor during the reigns of Emperor Wenzong and Emperor Wuzong. He was viewed as a Li Faction leader in the Niu-Li Factional Struggles.
It is not known when Chen Yixing was born. It was said that his family had its origins south of the Yangtze River, but had, for generations, lived in Yingchuan (潁川, in modern Luoyang, Henan). Neither his grandfather Chen Zhong (陳忠) nor his father Chen Yong (陳邕) was listed with any offices in the table of the chancellors' family trees in the New Book of Tang, suggesting that neither had an official title. He had at least three younger brothers, Chen Xuanxi (陳玄錫), Chen Yize (陳夷則), and Chen Yishi (陳夷實).
In 812, during the reign of Emperor Xianzong, Chen passed the imperial examinations in the Jinshi class. Thereafter, he served on the staffs of several regional governors. As of the end of Baoli era (825-827) of Emperor Xianzong's grandson Emperor Jingzong, Chen was serving as an imperial censor with the title of Shiyushi (侍御史), and serving at the eastern capital Luoyang, when he was made Yubu Yuanwailang (虞部員外郎), a low-level official at the ministry of public works (工部, Gongbu). He continued to serve at Luoyang.
In 829, during the reign of Emperor Jingzong's brother Emperor Wenzong, Chen Yixing was recalled to the capital Chang'an to serve as an imperial chronicler (起居郎, Qijulang), and he also served as an editor in imperial history, participating in the compilation of the chronicles of Emperor Xianzong's reign. After those chronicles of Emperor Xianzong's reigns were presented to Emperor Wenzong in 830, Chen was made Sifeng Yuanwailang (司封員外郎), a low-level official at the ministry of civil service affairs (吏部, Libu). In 831, he was promoted to be Libu Langzhong (吏部郎中), a supervisory official at the ministry of civil service affairs. Later in the same year, he was also made an imperial scholar (翰林學士, Hanlin Xueshi). In 834, he was also made a tutor to the Crown Prince Li Yong and ordered to attend to and lecture Li Yong on the Confucian classics once every five days. He was further given the office of Jianyi Daifu (諫議大夫), an advisory official, and put in charge of drafting edicts. In 835, he was made the deputy minister of worship (太常少卿, Taichang Shaoqing), and continued to serve in his capacities as imperial scholar, tutor to Li Yong, and drafter of edicts.