Tateyama Castle (Tateyama-jō) is a Japanese castle located in Tateyama, southern Chiba Prefecture, Japan. At the end of the Edo period, Tateyama Castle was home to the Inaba clan, daimyō of Tateyama Domain, but the castle is better known for its association with the former rulers of Awa Province, the Satomi clan. The castle was also known as "Nekoya-Jō".
Satomi Yoshiyori, virtually independent lord of all of the Bōsō Peninsula during the Sengoku Period, erected Tateyama Castle in 1580 to guard the entry to Edo Bay and the southern portions of his domains. After the Satomi clan was destroyed by the Tokugawa shogunate in 1614 and Tateyama Domain suppressed, the castle was allowed to fall into ruin.