World War II

Saipan International Airport was a sugarcane field before the Imperial Japanese Navy Air Service (IJNAS) constructed a temporary landing field on the site in 1933. The landing field was used for training purposes and had two runways configured in an "L" pattern. In 1937, the Navy began upgrading the airfield for full military use, despite an international law ban on constructing military facilities within the South Seas Mandate. Following the attack against the United States in 1941, the field was named Aslito Field (アスリート飛行場), based on the indigenous Chamoru name for the area of its location, As Lito.

The IJNAS assigned two squadrons of Mitsubishi A6M5a-52 Zeros to the airfield in mid-June 1944. These squadrons took part in the occupation of the Mariana Islands during the Battle of the Philippine Sea later that month, being almost wiped out by the American forces during the battle.

The airfield was captured by the United States Army 27th Infantry Division on June 18, 1944, during the Battle of Saipan. During the battle, a Zero from Guam actually landed at Aslito Airfield, the pilot being unaware that the field was under American control. As it landed, the aircraft was fired at and damaged, crashing at the end of the runway. The pilot survived and the plane was captured. The field was renamed Isely Field after United States Navy Commander Robert H. Isely who was killed on June 13, 1944, while strafing the base.

Once in American hands, Isely Field was quickly repaired and expanded by Seabees of the 3rd Battalion 20th Marines, to become Naval Advance Base Saipan. with the first P 47s of the 19th fighter Squadron landing on the 20th. The airfield was assigned to Twentieth Air Force B-29 Superfortress operations. The XXI Bomber Command had overall responsibility of the B-29 operations out of the Marianas bases, and Isely Field was to be used by the 73rd Bombardment Wing (which consisted of the 497th, 498th, 499th, and 500th Bombardment Groups).

On October 12, 1944, the first B-29 Joltin Josie The Pacific Pioneer piloted by Brigadier General Haywood S. Hansell commanding General of XXI Bomber Command and copiloted by Major Jack J Catton of the 873d Bombardment Squadron arrived at Isely Field. By November 22, over 100 B-29s were at Isely. The XXI Bomber Command was assigned the task of destroying the aircraft industry of Japan in a series of high-altitude, daylight precision attacks.

After several months of disappointing high level bombing attacks from Isely (and the other Twentieth Air Force airfields on Guam and Tinian), General Curtis LeMay, Commander of Twentieth Air Force issued a new directive that the high-altitude, daylight attacks be phased out and replaced by low-altitude, high-intensity incendiary raids at nighttime, being followed up with high explosive bombs once the targets were set ablaze. These nighttime attacks on Japan proved devastatingly effective, and the Superfortress missions from Isely Field led to massive destruction of industrial targets in Japan, with large industrial areas of Tokyo, Nagoya, and Osaka being repeatedly attacked by waves of American bombers flying from the Marianas until the war's end. In response to these attacks, most of the Japanese air attacks on the Mariana Islands between November 1944 and January 1945 targeted Isely Field.

The airfield and surviving World War II facilities were listed on the National Register of Historic Places in 1981 as the "Isely Field Historic District", and are a contributing element of the National Historic Landmark District Landing Beaches; Aslito/Isely Field; & Marpi Point, Saipan Island, which was designated in 1985.

Postwar

With the end of the war the wing's four bomb groups were all returned to the United States, with their B-29s either being flown to Clark Air Base in the Philippines for scrapping, or were flown to storage facilities in Texas or Arizona. The 73d Bomb Wing was reassigned to the United States in December 1945. The airfield was returned to civil control and it reverted to being called Aslito Field.

Saipan International Airport commenced operation on July 25, 1976, taking over from the nearby Kobler Field. Continental Micronesia (originally Air Micronesia) initially had its main hub at Kobler Field and then Saipan Airport. As time passed, the airline's general traffic to and from Saipan had decreased due to the breakup of the Trust Territory of the Pacific Islands; because the territory was subdivided into smaller political units, fewer people needed to travel to Saipan, the former capital of the trust territory. On July 15, 2008, the airline's Manila-Saipan flight, the final remaining Continental Micronesia directly operated flight, ended.

Japanese tourists began visiting Saipan in large numbers during the 1970s. The airfield and terminal were significantly upgraded in 1975 to handle widebody aircraft.

Northwest Airlines historically served Saipan from Tokyo-Narita using McDonnell Douglas DC-10 and Boeing 747 aircraft, while Japan Airlines (JAL) served Saipan from Narita and Osaka-Kansai using DC-10 and Boeing 767 aircraft respectively.