2nd Battalion, 5th Marines was formed in July of 1914 and immediately sailed to the Caribbean to quell political turmoil in the Dominican Republic and Haiti. In June 1917, the Battalion sailed for France with its parent regiment to participate in many of the major battles of World War I. Having fought during the Battle of Belleau Wood, Soisson, and the Meuse-Argonne Campaign, the Battalion was twice awarded the French Croix de Guerre with Palm and one Gold Star. To this day, members of the Battalion wear the French Fourragere representing these award. Following the armistice of 1918 2nd Battalion, 5th Marines was assigned to occupation duties in Germany until their return to Quantico, Virginia in August of 1919.

Beginning in 1920, the Battalion began guarding US Mail trains throughout the United States. In 1927 the Battalion was sent to Nicaragua to fight bandits and to supervise the 1928 Nicaraguan national elections. In 1941, 2nd Battalion, 5th Marines joined the newly-formed 1st Marine Division at New River, North Carolina, but later relocated to the west coast of the United States. During World War II the Battalion fought in the battles of Guadalcanal, Cape Gloucester, Peleliu, and Okinawa. Following the Japanese surrender the Battalion was assigned to occupation duty in Northern China until 1947, at which time they returned to the United States.

Immediately following the 1950 North Korean invasion of South Korea, 2nd Battalion, 5th Marines sailed from Camp Pendleton, California to defend the Pusan Perimeter as a part of the famous “Fire Brigade”. The Battalion would also participate in the landing at Inchon, the liberation of Seoul, the Chosin Reservoir Campaign, and the defense of the East, Central, and Western Fronts before the war was over. From July 1953 to February 1955, 2nd Battalion, 5th Marines assisted in the defense of the Korean de-militarized zone, after which they again returned to Camp Pendleton.

In April 1966, the Battalion deployed to the Republic of Vietnam and would remain there until 1971. During this time 2nd Battalion, 5th Marines participated in combat operations at Hue City, Que Son, Phu Bai, Dong Ha and Phu Loc. Immediately after their return to Camp Pendleton in 1971 the Battalion joined Operation New Arrival, the relocation of Southeast Asian refugees to the United States.

During the next fifteen years the Battalion deployed regularly as part of the Marine Corps Unit Deployment Program. In December 1990, 2nd Battalion, 5th Marines sailed for the Persian Gulf in support of Operations Desert Shield / Desert Storm and later landed in Saudi Arabia and participated in the liberation of Kuwait. During the return transit to the United States the Battalion was diverted to Bangladesh in order to provide humanitarian relief as part of Operation Sea Angel.

In 1993, 2nd Battalion, 5th Marines deployed as the Battalion Landing Team for the 11th Marine Expeditionary Unit (Special Operation Capable) and participated in operations in Rwanda and Somalia. In 1995 the Battalion began regular deployments to Okinawa for service as the Battalion Landing Team for the 31st Marine Expeditionary Unit (Special Operations Capable) and participated in several operations in East Timor.

2nd Battalion, 5th Marines is the most highly decorated battalion in the United States Marine Corps.