3d Marine Division operates as a Stand-In Force in the first island chain to secure, seize, or defend key maritime terrain in order to deny and disrupt adversary actions in support of the Fleet, the Joint Force, and partnered and allied forces.

3d Marine Division has five major subordinate elements: 3d Marine Littoral Regiment based in Hawaii and 12th Marine Regiment, 4th Marine Regiment, 3d Reconnaissance Battalion, and Headquarters Battalion based in Okinawa, Japan.

The 3d Marine Division was officially activated Sept. 16, 1942 at Camp Elliott, San Diego, California.  Most of the Division’s first members were drawn from the 9th Marines, commanded by Colonel Lemuel C. Shepherd Jr., who later became the 20th Commandant of the Marine Corps.  Major General Charles D. Barrett was the first Commanding General of the Division.  By Aug. 1943, the Division was based at Guadalcanal where special training and rehearsals for the Bougainville operation intensified.  The Division landed at Empress Augusta Bay, Bougainville, Nov. 1, 1943.  For approximately two months, the Division participated in its first fight against heavy enemy resistance.  After the transfer of command in the area to the Army's XIV Corps, the last elements of the Division returned to Guadalcanal Jan. 16, 1944.

Following the Bougainville operation, the Division began training for the next campaign.  Instructions received in Feb. 1944 led to planning for an operation against the Japanese on Emirau Island.  The projected Emirau operation was subsequently cancelled and instructions were received to instead plan an operation against enemy forces at Kavieng, New Ireland.  This operation was also called off.  A few days later, the Division began training for the amphibious assault against the Japanese on Guam.

The Division left Guadalcanal on June 2-3, 1944 and sailed for Kwajalein, Marshall Islands, en route to the Marianas.  It remained afloat off of Saipan June 15-18, 1944 as part of the reserve force for the Saipan operation, conducted by the 2d and 4th Marine Divisions in conjunction with the Army’s 27th Infantry Division.  With the situation on Saipan under control, the Division returned to its staging area in preparation for the Guam operation.

On July 21, 1944, the Division landed on the western beaches of Guam near Asan Point.  After twenty days of savage fighting, the Division troops reached the northern coast of the island. Guam was declared secure Aug. 10, 1944.  The Division continued conducting security operations on Guam until its departure for the Iwo Jima campaign in Feb. 1945.

Initially, the Division remained in reserve off the coast of Iwo Jima.  The Division landed on Feb. 24, and the next morning the 3d Marine Division launched an attack in its zone between the 4th and 5th Marine Divisions.  The 3d Marine Division faced well-organized and determined enemy resistance.  The terrain, ideal for defense, was heavily fortified by pillboxes, caves, and covered artillery emplacements.  Progress was slow and casualties were heavy during the first few days of fighting.  The Division slowly pushed the enemy back and, by Mar. 3, severed the last enemy east-west artery of communication by occupying positions overlooking the sea.  The 3d Marine Division secured its zone of action Mar. 11, and then initiated intensive patrolling and security operations.  On Mar. 16, units of the 3d Marine Division relieved elements of the 5th Marine Division and delivered the final attack of the Iwo Jima operation - a drive to Kitano Point.  Iwo Jima was declared secure on the same day.  On Apr. 4, the 3d Marine Division was relieved by U.S. Army units.

By mid Apr. 1945, the Division was back on Guam preparing for the next operation. On Aug. 3 1945, the Division received initial plans for Operation Olympic, which called for an amphibious landing of Kyushu in early Nov. 1945. The 3d Marine Division, along with the 2nd and 5th Marine Divisions, was assigned to the V Amphibious Corps for the operation. Japan's agreement to cease hostilities and subsequent surrender cancelled Operation Olympic, and the Division remained on Guam until it was deactivated on Dec. 28, 1945.

The Division was reactivated on Jan. 7, 1952 at Camp Pendleton, California.  Immediately after its activation, the Division began intensive combat training.  During the remaining part of 1952, elements of the Division participated in numerous exercises and experimentation with new concepts, including vertical envelopment, airborne operations and attack, and defense against atomic weapons and missiles.

In Aug. 1953, the 3d Marine Division arrived in Japan to support the 1st Marine Division in the defense of the region.  In Mar. 1956, the Division moved to Okinawa and remained there as an expeditionary force-in-readiness until 1965.

On May 6, 1965, the 3d Marine Division opened the Marine compound at the Da Nang Air Base in Vietnam.  The Division subsequently operated combat bases at Da Nang, Phu Bai, Quang Tri and Dong Ha.  The Division departed Vietnam in November 1969 and moved to Camp Courtney, Okinawa, where it is presently located.

From 2004 to 2011, elements of the 3d Marine Division participated in Operation Iraqi Freedom.  From 2004 to 2014, elements of the 3d Marine Division participated in Operation Enduring Freedom in Afghanistan.  From Mar. to May 2011, elements of the Division participated in the joint humanitarian relief effort Operation Tomodachi in the wake of the Tohoku earthquake and tsunami.

Today, the 3d Marine Division remains forward deployed in the western Pacific, prepared to fight and win alongside allies and partners with the technology of today while experimenting with the tools, systems, and organization for the force of tomorrow.