Château de Fukuhara, Mountain castle in Hitachi Province, Japan

Fukuhara Castle stood in present-day Fukuhara, Otawara, Tochigi Prefecture; sources place it in Shimotsuke Province, not Hitachi. It was a hilltop castle of the Nasu clan, also called Kitaoka Castle or Fukuhara Kitaoka Yakata, with a related earthwork, Fukuhara Yōgai Castle, on the low hill to the south. Today most of the site is farmland and no prominent remains survive.

Fukuhara Castle was built in the early Kamakura period by Fukuhara Yukitaka and served as the residence of the Nasu clan for about 300 years. After the split of the upper and lower Nasu families it became the seat of the upper Nasu. Following that family's fall in 1514, the Fukuhara family effectively held it alongside Sakurayama Castle. In 1610 Nasu Sukekage established the Nasu domain and built the Fukuhara jinya within the castle grounds; it was abandoned in 1681 when the third lord, Nasu Sukeyasu, was transferred to Karasuyama.

The castle site is now mostly farmland, with no prominent remains left to see. Its name survives in the place name Fukuhara in Otawara, Tochigi Prefecture, and it was also called Kitaoka Castle or Fukuhara Kitaoka Yakata. A separate earthwork, Fukuhara Yōgai Castle, stood on the low hill to the south, and some sources treat that site as Fukuhara Castle.

The castle site is now mostly farmland, and no prominent remains survive above ground, so there are no walls or foundations to follow. Visitors should not expect a marked trail or interpretive signs; the location is best identified by its position in Fukuhara, Otawara. Nearby on the lower southern hill stood the separate Fukuhara Yōgai castle, which some sources treat as Fukuhara Castle itself.

The castle site is now mostly farmland, with no visible remains. The name Fukuhara Castle is also applied to a separate fortification, Fukuhara Yōgai Castle, on the low hill to the south, and some sources treat that site as the real Fukuhara Castle.