The 5th Marine Division was a United States Marine Corps infantry division. Created during World War II, the 5th Division saw its first combat action during the Battle of Iwo Jima in World War II where it earned the Presidential Unit Citation as part of the invasion force awarded and sustained the highest number of casualties amongst the invasion force. The division was to be part of the planned invasion of the Japan homeland before Japan surrendered. The 5th Division was disbanded in 1946.