The 603rd Tank Destroyer Battalion was a tank destroyer battalion of the United States Army active during World War II. The battalion was formed in March 1941 as the 3rd Infantry Division Provisional Antitank Battalion, and on 14 December was redesignated as the 603rd Tank Destroyer Battalion, in line with the reorganisation of the anti-tank force. It remained in the United States until 1944, when it was moved to the United Kingdom, deploying into Normandy in late July equipped with M18 Hellcats. The battalion was attached to the 6th Armored Division, with which it would serve for the duration of the campaign in North-West Europe.