At the beginning of the Meiji era, the Army Ministry administered the castle, and the Nagoya Detached Garrison and barracks were [dispersed] on the castle grounds. Transferred to the Imperial Household Ministry in 1893, the castle became the Nagoya Imperial Villa. In 1930, after the abolition of the Imperial Villa, the castle was brought under the administration of the City of Nagoya and was opened to the public in February of the following year.

In May 1945, due to the air raids on Nagoya during World War II, buildings such as the main and small donjons, ad the Hommaru Palace were burnt down. Fortunately, three towers, three gates, and 1,047 paintings on the sliding doors and walls of the palace survived the fire and have been designated as important national cultural assets. In 1959, the main and small donjons, and the main gate were practically restored to their original forms. — from the entrance billboard of Nagoya Castle