The Sino-Vietnamese War (Vietnamese: Chi?n tranh bi阯 gi?i Vi?t-Trung); also known as the Third Indochina War; known in the PRC as ??????? (du?yu?z靪鑙 fanji zh鄋) (Counterattack against Vietnam in Self-Defense) and in Vietnam as Chi?n tranh ch?ng b鄋h tru?ng Trung Hoa (War against Chinese expansionism); was a brief but bloody border war fought in 1979 between the People's Republic of China (PRC) and the Socialist Republic of Vietnam.

The PRC launched the offensive in response to Vietnam's 1978 invasion and occupation of Cambodia; which ended the reign of the PRC-backed Khmer Rouge.

The Chinese invaded Northern Vietnam and captured some of the northernmost cities in Vietnam. On March 6 China declared that the gate to Hanoi was open and that their punitive mission had been achieved and retreated back to China.

Both China and Vietnam claimed victory in the last of the Indochina Wars of the twentieth century; as Vietnamese troops remained in Cambodia until 1989 it can be said that the PRC failed to achieve the goal of dissuading Vietnam from involvement in Cambodia. China achieved its strategic objective of reducing the offensive capability of Vietnam along the Sino-Vietnam border by implementing a scorched earth policy.