Yoshida Castle, Japanese castle in Toyohashi, Japan

Yoshida Castle is a Japanese fortress in Toyohashi that sits on elevated ground above the city. The reconstructed three-story Kurogane Turret stands among the old stone walls and offers views over the surrounding streets and buildings.

Makino Kohaku built the castle in 1505 on the orders of Imagawa Ujichika, to guard against the Matsudaira clan's advance into eastern Mikawa. It changed hands repeatedly among the Imagawa, Matsudaira and Toda until Tokugawa Ieyasu took it in 1565 and appointed Sakai Tadatsugu as castellan. In 1590 Ikeda Terumasa received the castle and began a major rebuild, but he was transferred to Himeji in 1601 and the keep was never completed.

The stone walls of the honmaru and the riverside kuruwa incorporate many granite blocks bearing yaaana (arrow-notch) marks and quarry inscriptions, evidence of the construction attributed to Matsudaira Tadatoshi's time. The northwest corner, beneath the reconstructed Kurogane Yagura, was built under Ikeda rule using chert. The castle also appears in Hiroshige's Fifty-three Stations of the Tōkaidō, one of only two stations shown with both bridge and castle.

The Kurogane Turret keeps 10:00–15:00 hours and closes on Mondays and over the New Year holidays, opening instead when a Monday is a public holiday; entry is free. Reach the park in about five minutes on foot from Toyohashi Park-mae or Shiyakusho-mae tram stops, or about twenty minutes from Toyohashi Station.

The castle's early name is uncertain: the 16th-century Ushikubo-ki calls it Yoshida Castle, while later works such as Ushikubo Mikkō-ki and Miyajima-denki call it Imabashi Castle, and Imabashi Monogatari lists older names Mine-no-jō and Okasawa-jō. A 1909 Toyohashi city history credits Imagawa Yoshimoto with the change from Imabashi to Yoshida.