Schofield Barracks was established in 1908 to provide defense of Pearl Harbor and the island of O'ahu. The post was named for Lieutenant General John M. Schofield, Commanding General of the Army from 1888-1895, who observed O'ahu's strategic location as a naval base.

During World War II Schofield Barracks was used mainly as post for garrison troops and base for the 25th Infantry Division. Wheeler Army Airfield (now part of the Barracks) was, during World War II, a priority target of the Attack on Pearl Harbor, and suffered serious damage; some pilots did manage to launch in a lull in the attack (including one in his pajamas) and take down a few of the attackers. Wheeler later became an Air Force Base, before returning to Army control in the 1990s.

Located on over 17,000 acres, Schofield is the largest army post in Hawaii. It is also home to the 25th Infantry Division, also known as the "Tropic Lightning Division", since 1941 and home to the 8th Theater Sustainment Command. Schofield is the Command Headquarters of the U.S. Army, Hawaii (USARHAW) which is a sub-command of U.S. Army Pacific (USARPAC) headquartered at Fort Shafter, also on O'ahu.