Gradačac Castle (Bosnian: Dvorac Gradačac) is a castle located in Gradačac in Bosnia and Herzegovina.
Gradačac Castle has a fort with 18-meter high walls built between 1765 and 1821, and a 22-meter high watchtower, built in 1824 by Husein-kapetan Gradaščević on foundations made originally by the Romans.
It is finished in the 19th century. In 1831 general rallied the Bosnians against the Turkish occupation and drove the Ottomans out to Kosovo, winning Bosnia its sovereignty for the coming year. Therefore, fortification has great historic importance for Bosnians. It has been recently renovated.