Dayi Daoxin (Chinese: 道信， Wade-Giles: Tao-hsin) (Japanese: Dōshin) (580–651) was the fourth Chán Buddhist Patriarch, following Jianzhi Sengcan 僧璨 (died 606) (Wade-Giles: Chien-chih Seng-ts'an; Japanese: Kanchi Sosan) and preceding Hongren Chinese: 弘忍) (601–674).
The earliest mention of Daoxin is in the Hsü kao-seng chuan (Further Biographies of Eminent Monks (645) (Pin-yin, Xu gao-seng zhuan; Japanese, Zoku kosoden;) by Tao-hsuan (d. 667)) A later source, the Ch'üan fa pao chi (Annals of the Transmission of the Dharma-treasure), written around 712, gives further details of Daoxin's life. As with many of the very earliest Chan masters, the accuracy of the historical record is questionable and in some cases, contradictory in details. The following biography is the traditional story of Daoxin, culled from various sources, including the Wudeng Huiyuan (Compendium of Five Lamps), compiled in the early thirteenth century by the monk Dachuan Lingyin Puji (1179–1253).