Osaka Castle is a Japanese castle in Chūō-ku, Osaka, Japan. The castle and fortress are one of Japan's most famous landmarks and it played a major role in the unification of Japan during the sixteenth century of the Azuchi-Momoyama period.

Japanese castles are fortresses constructed primarily of wood and stone. They evolved from the wooden stockades of earlier centuries and came into their best-known form in the 16th century. Castles in Japan were built to guard important or strategic sites, such as ports, river crossings, or crossroads, and almost always incorporated the landscape into their defenses.