Okazaki Castle is a Japanese castle located in Okazaki, Aichi Prefecture, Japan. At the end of the Edo period, Okazaki Castle was home to the Honda clan, daimyō of Okazaki Domain, but the castle is better known for its association with Tokugawa Ieyasu and the Tokugawa clan. The castle was also known as "Tatsu-jō " (龍城).

Okazaki is a city located in Aichi Prefecture, Japan. As of 1 October 2019, the city had an estimated population of 386,999 in 164,087 households, and a population density of 999 persons per km². The total area of the city was 387.20 km2 (149.50 sq mi).