Sayama fudōson, Buddhist temple in Kami-Yamaguchi, Japan.

Sayama fudōson is a Tendai Buddhist temple in Kami-Yamaguchi, Tokorozawa. Its wooden main hall stands on a stone base, with weathered brown timber walls, a gray tiled roof with upturned eaves and a round finial, and a dark plaque with gold characters above studded double doors reached by a wooden stair.

Buildings collected privately by Yasuzaemon Tsutsumi from across Japan in the 1940s and 1950s were moved to this site and first shown as part of the UNESCO Village theme park. In 1975, with help from Kan'ei-ji, the site opened as a Tendai sect temple. Its main hall, the Shichiken-dō moved from Kyoto's Higashi Hongan-ji, burned down in 2001.

The temple is known for the hatsumōde prayers held by the Saitama Seibu Lions baseball team each year in late March, just before the season opens. Its annual observances also include Hana-matsuri from 1 to 8 April, Shichi-go-san in late October and November, and a goma fire rite every Sunday at 14:00.

The temple is a five-minute walk from Seibu-Kyujo-mae Station, served by the Seibu Sayama Line and the Leo Liner people mover. The main hall burned down in 2001, so the halls open to visitors are the relocated Edo-period structures. The grounds are not barrier-free: wooden stairs with railings lead up to the halls.

Three halls from the Tokugawa Hidetada mausoleum at Zojo-ji in Shiba Park, Tokyo — the chokugakumon, chozubachi-mon and onari-mon — were moved here in 1963 and are now Important Cultural Properties. They belong to a private owner, not to Fudo-ji itself.