1963 South Vietnamese coup d'état

On November 1, 1963, President Ngô Đình Diệm and the Personalist Labor Revolutionary Party of the Republic of Vietnam (South Vietnam) were deposed by a group of CIA-backed Army of the Republic of Vietnam officers who disagreed with Diệm's handling of the Buddhist crisis and the North Vietnamese-Viet Cong (VC) threat to South Vietnam. During South Vietnam's later years, some referred to the coup as Cách mạng 1-11-1963 (The 1st November 1963 Revolution).

The Kennedy administration had been aware of the coup planning, but Cable 243 from the United States Department of State to U.S. Ambassador to South Vietnam Henry Cabot Lodge Jr. stated that it was U.S. policy not to try to stop it. Lucien Conein, the Central Intelligence Agency's liaison between the U.S. Embassy and the coup planners, told them that the U.S. would not intervene to stop it. Conein also provided 3 million Vietnamese piastres (approx. $42,000 USD) to reward military units that joined the coup. The decision to support the coup stemmed from the Kennedy administration's growing conviction that Diem was incapable of uniting the South Vietnamese people against communism. Diem's government was also increasingly seen as repressive, particularly after his violent crackdown on Buddhist protests.

The coup was led by General Dương Văn Minh and started on 1 November 1963. It proceeded smoothly, for many loyalist leaders were captured after being caught off-guard, and casualties were light. Diệm was captured and assassinated the next day, along with his brother and advisor Ngô Đình Nhu.