Marine Aircraft Group 31 was commissioned at Cherry Point, North Carolina on February 1943.
From October 1943 until October 12, 1945, the Group operated throughout the Pacific Area and played an integral part in the battle for Okinawa. Subsequent to the seizure of Okinawa, MAG-31 Squadrons continued their part in the war conducting operations from Yantan Airfield on the island. While on Okinawa, MAG-31 was commanded by Colonel John C. Munn, who later became a Lieutenant General and Assistant Commandant of the Marine Corps.
On October 12, 1945, the Group departed Okinawa for Yokosuka, Japan becoming the first Marine land based Group to operate in the Japanese homeland. The Group was transferred from 2d MAW to the 4th MAW on February 12, 1946, and then to the Fleet Marine Force Pacific on March 13, 1946.
The Group returned to the United States on July 5, 1946 and was stationed at the Marine Corps Air Station Miramar, San Diego, California, until it was decommissioned on May 31, 1947.
MAG-31 was reactivated on March 17, 1952 at Cherry Point, North Carolina and transferred to Marine Corps Air Station, Miami, Florida operating as a part of the 3d MAW until it was again decommissioned in 1958.
On November 1, 1961, MAG-31 was again reactivated and stationed at its present home, the Marine Corps Air Station, Beaufort, South Carolina, as part of the 2d MAW.