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 145, the squadron re-deployed to Peiping, China to participate in the post-war occupation of Northern China. The squadron was soon called to action on the Korean peninsula at the outbreak of hostilities. Deployed to Korea in October 1950, HS-12 distinguished itself in combat during the Battle of the 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.
In May 1965, H&MS-12 deployed in support of combat operations at Chu Lai and Hoa, Republic of Vietnam. Returning to Iwakuni in February 1970, elements of H&MS-12 returned to Vietnam, participating in combat operations at Bien Hoa from May 1972 to January 1973.
From January 1973 until September 1988, H&MS-12 continued to provide support for aviation units assigned to Marine Aircraft Group 12 (MAG-12) and various units throughout the Western Pacific. On 1 October 1988, the squadron was combined with H&MS-15 and re-designated as Marine Aviation Logistics Squadron 12 (MALS-12). During December 1989, MALS-12 deployed a substantial detachment to the Philippines in support of MAG-12 operations during the attempted coup.
In 1990, MALS-12 supported the pre-deployment aircrew training and aircraft grooming of two squadrons in preparation for their deployment to Southwest Asia for participation in Operation DESERT SHIELD/DESERT STORM.
In July 1992, MALS-12 was again brought to the forefront with participation in the base closures of Naval Air Station Cubi Point in the Republic of the Philippines and Naval Air Facility Kadena, Okinawa. MALS-12 provided the leadership, knowledge, and manpower required to distribute critical support equipment and other mission essential assets.
During June 1993, in concert with the six aircraft AV-8B detachment to the 31st Marine Expeditionary Unit (31st MEU), MALS-12 began the on-going support to the 31st MEU and the USS Belleau Wood by providing an AV-8B Peculiar Contingency Support Package.
Exercise SOUTHERN FRONTIER, a MAG level, multiple squadron deployment to Royal Australian Air Force (RAAF) Base Darwin, Australia, began in 1994, and MALS-12 was there. As a precursor to the success of the operation, MALS-12 participated in the largest ever ordnance off-load in Australia since World War II. Additionally, MALS-12 established liaison with the RAAF counterparts at RAAF Base Tindal, Australia to augment support of the F/A-18 aircraft.
Unit accolades include the Aviation Safety Award (1982), the Commandant’s Aviation Efficiency Trophy (1983-1984), and the Meritorious Unit Commendation for exceptional meritorious service from July 1984 to July 1986. In 1994 MALS-12 was recognized as the Marine Corps Aviation Association’s MALS of the Year, and was subsequently awarded the Navy Unit Commendation in April 1995. In 1996, MALS-12 was the recipient of the Secretary of Defense Award for Maintenance Excellence in the Medium Category. In 1999, MALS-12 was the recipient of both the Marine Corps Aviation Association’s MALS of the Year and the Secretary of Defense Award for Maintenance Excellence in the Medium Category. In 2001, MALS-12 received a second Meritorious Unit Commendation for exceptional meritorious service from 1 October 1998 to 31 January 2000. MALS-12 again proved worthy of recognition, as they were the recipients of the Donald E. Davis Award, presented by the Marine Corps Aviation Association for MALS of the Year in 2012 and 2014.