Oki Kokubun-ji, Buddhist temple in Ikeda, Okinoshima, Japan

Oki Kokubun-ji is a Shingon temple of the To-ji school on a hill north of the Yabi plain on Dogo, the main island of the Oki archipelago. Its main hall, rebuilt in 2014 after a 2007 fire, stands on the site of the ancient provincial monastery, where excavation from 2009 revealed pillar foundations. Several foundation stones and roof tiles from the old monastery are kept in the grounds.

The temple was founded in 741 when Emperor Shōmu launched an initiative to establish Buddhist monasteries throughout all Japanese provinces. This program significantly shaped the religious landscape of the Nara period.

Each year on April 21, the anniversary of Kōbō Daishi's death, the temple hosts the Rengee-mai dance, a masked silent drama in the style of ancient bugaku. Seven pieces are performed today, including "Mugi-yaki-mai" and "Nemuri Butsu". The dance was designated an Important Intangible Folk Cultural Property in 1977, but its old masks and props burned in the 2007 hall fire.

The temple stands on a hill north of the Yao Plain, about a 10-minute walk from the "Kokubunji-mae" bus stop, which is served by buses from Saigo Port. The main hall, rebuilt in 2014 after a 2007 fire, houses the principal image. The grounds are a designated national historic site, and the nearby nun's temple ruins are about 500 meters southeast.

The temple grounds hold a stone monument marking the site where Emperor Go-Daigo is said to have stayed after his exile to Oki in 1332. The claim is disputed, since Kuroki Gosho on Nishinoshima is also put forward as his residence, so the exact location remains unsettled.