The Battle of Lộc Ninh was a major battle fought during the Easter Offensive during the Vietnam War, which took place in Bình Long Province, South Vietnam between 4 and 7 April 1972. Towards the end of 1971, North Vietnamese leaders decided to launch a major offensive against South Vietnam, with the objective of destroying Army of the Republic of Vietnam (ARVN) units and capturing as much territory as possible, in order to strengthen their bargaining position in the Paris Peace Accords. On 30 March 1972, two People's Army of Vietnam (PAVN) divisions smashed through the Vietnamese Demilitarized Zone, marking the commencement of the Easter Offensive. They quickly overwhelmed South Vietnamese units in the I Corps Tactical Zone. With the rapid collapse of South Vietnamese forces in the northern provinces of South Vietnam, PAVN and Viet Cong (VC) forces began preparing for their next offensive, targeting Bình Long Province in the rubber plantation region north of Saigon. On 4 April, the VC 5th Division opened their attack on Lộc Ninh, defended by the ARVN 9th Infantry Regiment. After three days of fighting, the vastly outnumbered ARVN forces, though well supported by American air power, were forced to abandon their positions in Lộc Ninh.

The 18th Division was an infantry division in the III Corps of the Army of the Republic of Vietnam (ARVN). The U.S. Military Assistance Command Vietnam considered the 18th as undisciplined and was well known throughout the ARVN for its "cowboy" reputation. In 1975 the 18th was made famous for its tenacious defense of Xuân Lộc, the last major battle before the Fall of Saigon.