The unit sailed for France on June 14, 1918. Subsequently, the unit fought at Bois de Belleau, Vierzy, Château-Thierry, Pont-a-Mousson, Limey Sector, Fleury, Muese Argonne, Blanc Mont, St Michiel, Leffincourt and Soissons. The unit's various outstanding performances earned it the Croix de Guerre "Cross of War" from the French government.
After being deactivated in 1935, the unit was reconstituted in 1940. The unit fought at Guadalcanal, New Guinea, Peleliu and Okinawa. At the end of the war, the unit was again deactivated in 1946.
In 1949, the unit was yet again activated for service on the Korean Peninsula. The unit fought in and around the Pusan Perimeter, Inchon, Seoul and the Chosin Reservoir. The unit left Korea in 1953 and 1954, and moved its operations to Camp Pendleton in San Diego County.
After seeing other Marine units enter the Vietnam War in 1965, the 3rd of the 5th moved its operations to the South East Asia theater in June 1966. From then until March 1971, the unit operated in and around Chu-Lai, Da Nang, Quang Nam, Khe Sanh, Hue, An Hoa and in the Que Son Valley.
In December of 1990, the 3rd of the 5th fought during Desert Storm in the Persian Gulf. The unit distinguished itself throughout these operations, but performed particularly well at Al Wafrah, Kuwait. In 2003, the unit was again deployed to the Middle East to support operations related to Operation Iraqi Freedom.