Shubin (dates of birth and death unknown) was a monk in the early Heian period. His birthplace was unknown. He was called Shubin Sozu (high-ranking priest).
He learned the Three Shastras (Three Treatises) and the Hosso (Dharma Characteristics school) from Gonso of Iwabuchi-dera Temple in Yamato Province among others, and had thorough knowledge of Shingon Esoteric Buddhism. When Emperor Saga granted To-ji Temple to Kukai and simultaneously granted Sai-ji Temple to Shubin in 823. Having been a rival in most matters with Kukai, the monk of To-ji Temple, on being defeated by him in a competition for inducing rainfall by prayer when a draught hit in 824, he shot an arrow at Kukai, but its path was interrupted by a Jizo Bosatsu (Jizo Bodhisattva). The 'Yatori Jizo' (Jizo Bosatsu which protected Kukai from the arrow) is now enshrined beside the site of the demolished Rasho-mon Gate. It is believed that Sai-ji Temple gradually fell into ruin in those days as a result.