The Marine Wing Headquarters Squadron (MWHS) provides administrative and supply support for a Marine Aircraft Wing Headquarters (MAW HQ). The MAW HQ is a separate organization that directs and coordinates the operations of the MAW. The MAW HQ contains the wing commander (commanding general) and assistant wing commander, their personal staffs (aides-de-camp, drivers, etc.), and the chief of staff, the general staff divisions (G-1 through G-6), and the special staff departments (public affairs officer, wing inspector, staff judge advocate, wing medical officer, and wing chaplain).
The wing commander fights the MAW from his operational command post located in the Tactical Air Command Center (TACC) maintained by the Marine Tactical Air Command Squadron (MTACS).
The squadron was called to action on the Korean peninsula at the outbreak of hostilities.
Deployed to Wonson, Korea in October 1950, HS-12 distinguished itself in combat during the Battle of Chosin Reservoir, East Central Front, and the Western Front Campaigns until June 1956.
In July 1956, the newly re-designated Headquarters and Maintenance Squadron 12 (H&MS-12) re-deployed from Korea to its current home base at MCAS Iwakuni, Japan.
Activated as Headquarters and Services Squadron 12 (HQSQ-12) on 1 March 1942, the squadron was assigned in May of that year to the 1st Marine Aircraft Wing and was re-designated on 1 July as Headquarters Squadron 12 (HS-12). Throughout World War II, HS-12 was attached to both the 1st and 2nd Marine Aircraft Wings and participated in numerous campaigns throughout the Northern Solomons, Leyte, Luzon, and the Southern Philippines.
In October 1945, the squadron re-deployed to Peiping, China to participate in the post-war occupation of Northern China.