Château de Hiwasa, Japanese castle in Minami, Japan.

Hiwasa Castle is a Japanese fortification located on a forested hilltop in Minami, featuring a reconstructed main tower and defensive walls. The site overlooks the surrounding landscape and demonstrates the standard layout of a feudal-era stronghold.

Hiwasa Castle was built between 1570 and 1573 by Hiwasa Hizen-no-kami, a retainer of Hosokawa Sanezumi, to resist Chōsokabe Motochika's advance. In 1577 he surrendered to Chōsokabe Chikayasu's army and died; his brother Gontō took the name Hizen-no-kami and cooperated with the Chōsokabe. After 1585 the family moved to Osaka and later Tosa, and the castle was abandoned by 1596.

The castle is also called Izutsu Castle. The Hiwasa family served the Awa Hosokawa clan; after the 1585 arrival of the Hachisuka, the castle's holder Gondo moved to Tenma in Osaka and became a ronin, taking the name Hamagorozaemon in 1596 in Tosa. The castle was abandoned around then. The Hachisuka later recalled the family, granting 50 koku and samurai status.

The castle hill is a twenty-minute walk from JR Hiwasa Station on the Mugi Line, or about twenty-five minutes from the Hiwasa bus stop on the Tokushima Bus Muroto-Niimi-Anan Osaka line. Only the observation deck of the 1978 mock keep is open to the public; the stone walls are modern reconstructions, not original remains.

The keep on the hill is a 1978 concrete reconstruction, built as an outdoor activity facility for workers and now open only as an observation deck. No original buildings or stone walls survive; the present stonework was not reused from the feudal castle.