Itter Castle is a 19th-century castle in Itter, a village in Tyrol, Austria. In 1943, during World War II, it was turned into a Nazi prison for French VIPs. The castle was the site of an extraordinary instance of the U.S. Army, German Wehrmacht, Austrian Resistance, and the prisoners themselves fighting side-by-side against the Waffen-SS in the battle for Castle Itter in early May 1945 before the end of the war in Europe.

The Battle of Castle Itter was fought on 5 May 1945, in the Austrian village of Itter in the North Tyrol region of the country, during the last days of the European Theater of World War II.