The battalion was first formed on May 12, 1943, at Marine Corps Base Camp Pendleton, California. It was composed, with the exception of 2 officers, entirely of reservists. It was the first unit to capture Japanese mandated territory in the Pacific. It participated in the Battle of Kwajalein, Battle of Saipan, Battle of Tinian, and the battalion's last major operation in World War II was the Battle of Iwo Jima.

Late in 1946, a group of World War II veterans began meeting at the Marine Corps Recruit Depot on a volunteer basis. This became the formation of the first organized Marine Corps Reserve unit in San Diego. The unit was officially designated as the 11th Tank Battalion in 1947 and became home for a headquarters and a tank company.