The 405th Fighter Group was a fighter bomber unit of the United States Army Air Force in World War II. The group flew P-47 Thunderbolts in the European Theater of Operations (ETO) starting with the buildup to the Invasion of Normandy ("D-Day") through the end of the war in Europe. The 405th was a unit of the Ninth Air Force, IX Fighter Command, IX Tactical Air Command, 84th Fighter Wing. The 405th was primarily assigned to support Patton's Third Army. The group consisted of the 509th, 510th, and 511th Fighter Squadrons, plus headquarters elements. The group consisted of 73 aircraft.