Zenryuji, Buddhist temple in Katō, Japan

Zenryuji is a Shingon temple of the Koyasan school on Mount Kōdani in Katō, Hyōgo Prefecture. Its main hall, rebuilt over seven years and completed in 1688, enshrines Yakushi Nyorai, Nikko Bosatsu and Gekko Bosatsu as hidden images. Two round pillars flanking the shrine are dated to the Kamakura period, and a small waterfall called Zenryū drips quietly in the temple grounds.

Tradition attributes the temple's founding to the monk Hōdō Sennin during the Taika era (645–650), with Gyōki later carving the main Yakushi triad. By the medieval period it was a Tendai complex of over fifty halls, repeatedly damaged by warfare, and by the early Edo period it had become a Kōyasan Shingon temple. In 1601 Lord Ikeda Terumasa granted it 27 koku of temple land, confirmed by a shogunate vermilion-seal charter under Tokugawa Iemitsu.

The temple belongs to the Kōyasan Shingon school (Kōyasan Shingon-shū), not Soto Zen. Its name comes from the "Zenryū" spring that founder Hōdō Sennin found dripping quietly between two rocks, giving the phrase "zenryū nari" (a silent waterfall). It is the sixth stop on the Harima Eight Yakushi pilgrimage, called the "manjushage temple", with its own pilgrimage song.

The temple stands in the hills of Kōdani, with the main hall reached along a path lined with the two sub-temples, Kanjō-in ("Kamin-dera") on the east side and Jimyō-in ("Shimo-dera") on the west. The 1854 sanmon gate, donated by Tsuji Heishichi Seijun of Ozawa village, marks the entrance; it was moved from a spot about 300 metres south. The sacred Zenryū waterfall and the replica pilgrimage stone Buddhas lie in the wooded slopes behind the main hall.

Many of the stone Buddhas lining the replica pilgrimage routes on the hill behind the main hall are headless; gamblers around the Meiji era are said to have carried the heads off as lucky charms. The temple's own waterfall, the Zenryū that gives it its name, is not a rushing fall but a quiet trickle of drops.