Hakuchi Castle, Hilltop castle in Shikoku, Japan.

Hakuchi Castle is a hilltop fortification in Ikeda, Miyoshi, Tokushima, at the crossroads of the old Awa, Tosa, Iyo and Sanuki provinces. Only earthen ramparts and cut slopes remain; most of the baileys, moats and warrior paths were destroyed when the Awano-sho inn was built. A stone monument and Onishi Shrine stand in the adjacent Hakuchi children's park.

In 1335 Kondo Kyotei, an official of the Tai estate, built a castle here and took the name Onishi, whose line held it for eight generations. The Onishi submitted to the Hosokawa and then the Miyoshi. In 1577 Chosokabe Motochika seized it as a base for unifying Shikoku; in 1585, after Toyotomi Hideyoshi's invasion, the Chosokabe withdrew to Tosa and the castle was abandoned.

The castle site is a designated historic site of Miyoshi City. Near the south side of the Awa no Sho inn, in Hakuchi Children's Park, stand a stone monument marking the castle ruins and Onishi Shrine, named after the Onishi clan who held the castle for eight generations.

Most of the castle's earthworks were destroyed when the Kanpo no Yado inn, now Awa no Sho, was built on the site. The stone monument marking the castle ruins and Onishi Shrine stand in a corner of Hakuchi Children's Park, just south of the inn's grounds. Only scattered earthen embankments and cut slopes remain in the surrounding area.

Most of the castle's earthworks were destroyed in the late Showa period during construction of the Kanpo no Yado inn, now Awa no Sho. Only a few earthen embankments and cut slopes survive nearby. A stone monument marking the castle site and Onishi Shrine stand in a corner of Hakuchi Children's Park, next to the inn grounds.