Shibata Castle, Japanese castle in Shibata, Japan.

Shibata Castle is a fortified site in Shibata, Niigata Prefecture, built on flat terrain between two river branches and wetlands. The defenses rely on natural moats and wide open spaces, while the surviving entrance gate and rebuilt stone walls show traditional construction methods.

Mizoguchi Hidekatsu started rebuilding the fortress in 1597 after receiving the territory from Toyotomi Hideyoshi, and major construction finished in 1654. The work stretched across several generations of the Mizoguchi family, who controlled the area until the Meiji period.

The castle's other name, Ayame-jo (Iris Castle), is recorded in Japanese sources alongside Shibata Castle, and the grounds are now laid out as Shibata Castle Site Park, a local recreation spot. In spring the park is known for its cherry blossoms and draws many visitors. A bronze statue of the first Mizoguchi lord, Hidekatsu, stands on the castle grounds.

Most of the castle grounds belong to the Japan Ground Self-Defense Force Shibata garrison, so only the Honmaru gate, the Ninomaru corner turret and the Tatsumi turret can be entered. The interior of the three-story turret inside the base is not open. The surrounding Shibata Castle Site Park is a public space, and the stone walls and moat on the south side of the Honmaru can be viewed from outside.

The Omote-mon gate holds status as an Important Cultural Property and remains one of the few original structures from the early fortress. Large sections of the site are now occupied by the Japan Ground Self-Defense Force, continuing a military presence at the location.