Iwamoto-ji (岩本寺) is a Chisan Shingon temple in Shimanto, Kōchi Prefecture, Japan.

Gyōki founded Iwamoto-ji in 729 after receiving an imperial command by Emperor Shōmu who had an interest in establishing a system of provincial temples in Japan.

He originally built a group of 7 temples to represent the seven stars and seven good fortunes described in Ninnō-gyō.

[2] Kōbō-Daishi arrived at Shimanto Town in 810 and added 5 shrines and 5 temples to the area over a span of 14 years.

Several fires caused by war (1573-1592) burned the temples down and were temporarily closed.