MACG-18 was formed 1 September 1967 in DaNang, Vietnam, at the height of US participation in the Vietnam Conflict. At that time the Group's component units were already deeply involved in combat, and its Hawk battalion was among the first US Marine units to land in Vietnam. From the very time of its formation, MACG-18 and it subordinated units with attachments scattered throughout the I Corps Tactical Zone, participated in every major campaign conducted in the northern area of South Vietnam until its departure from Vietnam. In recognition of their accomplishments during the Vietnam Conflict, MACG-18 and its units were awarded four Presidential Unit Citations, three Navy Unit Commendations and Meritorious Commendation.
The Group moved from Vietnam to Marine Corps Air Station Iwakuni, Japan in 1971, and was displaced again to Marine Corps Air Station Futenma, Okinawa, Japan, in 1975. Since the end of the war in Vietnam, MACG-18 has assumed a major role in joint, combined and Marine air-ground training and contingency operation in the Western Pacific.