Kindaichi Castle, Medieval castle ruins in Iwate Prefecture, Japan

Kindaichi Castle, also called Shinohe Castle, occupies a river terrace on the left bank of the Mabuchi River in Ninohe, Iwate Prefecture. Its earthworks divide the site into three enclosures: the upper, middle and lower compounds, the largest being the upper one at about 100 m east-west by 250 m north-south. Medieval and early modern ceramics have been found there.

Kindaichi Castle was built during the Sengoku period to serve military interests and monitor the region. The site functioned as a strategic stronghold for local clans maintaining control over surrounding lands.

The castle's name comes from the Kindaichi family, who, according to tradition, held the lower enclosure (shimodate); the upper enclosure was also called Shido Castle, after the Shido clan, and the middle one belonged to the Kirien clan. The three enclosures together were called Kindaichi Castle, though the details are unclear. Medieval and early modern ceramics have been excavated from the site.

The ruins lie on a river terrace of the Mabuchi River in the Kindaichi-Nakamachi area of Ninohe, Iwate Prefecture. The site is divided by dry moats into three enclosures: Kami-tate, Naka-tate and Shimo-tate. The Kami-tate enclosure, also called Shido Castle, is the largest at about 100 m east-west by 250 m north-south.

Archaeological excavations at the castle site have uncovered everyday objects from when soldiers and staff lived here. These findings provide insights into daily life during the feudal military period.