A coup attempt by the Army of the Republic of Vietnam against President Ngô Đình Diệm was crushed after he falsely promised reform, allowing loyalists to rescue him.

On 11 November 1960, a failed coup attempt against President Ngô Đình Diệm of South Vietnam was led by Lieutenant Colonel Vương Văn Đông and Colonel Nguyễn Chánh Thi of the Airborne Division of the Army of the Republic of Vietnam (ARVN).

The Army of the Republic of Vietnam composed the ground forces of the South Vietnamese military from its inception in 1955 to the Fall of Saigon on 30 April 1975. Its predecessor was the ground forces of the Vietnamese National Army, established on 8 December 1950, representing Vietnam to fight in the First Indochina War against the communist Viet Minh rebels. At the ARVN's peak, an estimated 1 in 9 citizens of South Vietnam were enlisted, composed of Regular Forces and the more voluntary Regional Forces and the Popular Force militias. It is estimated to have suffered 1,394,000 casualties during the Vietnam War.

Ngô Đình Diệm was a South Vietnamese politician who was the final prime minister of the State of Vietnam (1954–1955) and later the first president of South Vietnam from 1955 until his capture and assassination during the CIA-backed 1963 coup d'état.