Shōkū (証空, November 30, 1177 – December 24, 1247), sometimes called Seizan (西山), was a disciple of Hōnen, founder of the Jōdo-shū Buddhist sect.

Shōkū later succeeded Jōhen, another disciple of Hōnen, as the head of a former Shingon Buddhist temple, Eikandō, established a separate branch of Jōdo-shū called the Seizan branch (after its namesake), and completed the transition of Eikandō from a Shingon temple into a Jōdo shū one.

After Hōnen had died, Shōkū also studied Tendai and esoteric Shingon Buddhism extensively with a focus on Pure Land teachings and practices.

This echoes the words of Hōnen where one should study Buddhist teachings, but then return to the humble self to be saved by Amida Buddha.

[2] This approach to Pure Land Buddhism won favor among the established Tendai sects, and so Shōkū was one of the few of Hōnen's disciples who was not exiled or executed in the year 1227, during the Karoku Persecution.