龍雲寺, Buddhist temple in Hamamatsu, Japan

Ryūun-ji is a Rinzai-shū Myōshin-ji temple in Irino-chō, Chūō-ku, Hamamatsu, with the mountain name Saikozan and Amida Nyorai as its principal image. Its main hall dates from the Genroku era, and its grounds contain the Muryōju and Shōjō gardens, laid out by Yasuo Kitayama for the 650th memorial of the first abbot.

Ryuun-ji follows the Rinzai school of Zen Buddhism, a tradition brought from China to Japan during the medieval period. The temple was established as a working religious site for the Hamamatsu area and continues to function as one today.

In 2017 the temple received a "world's largest Heart Sutra" brushed by calligrapher Shoko Kanazawa, and an exhibition of it is held every year. Kanazawa, born in 1985, began studying calligraphy as a child and is known for large-scale sutra works. The scroll is a focal point of visits to the temple.

The temple sits on a hillside outside the city center and is easiest to reach by car, though bus connections from Hamamatsu Station are also available. Wear sturdy shoes, as the paths across the grounds involve slopes and steps.

Along the entrance path, stone figures of rakan, the Buddha's disciples, are placed at intervals, each with a different pose and expression. There are 500 of them in the Buddhist tradition, and their presence is meant to give the sense of being accompanied as you walk toward the main hall.