In November 1963, President Ng nh Dim and the Personalist Labor Revolutionary Party of South Vietnam was deposed by a group of Army of the Republic of Vietnam officers who disagreed with his handling of both the Buddhist crisis and the Viet Cong threat to the regime. In South Vietnam, the coup was referred to as Cch mng 1-11-63 ("1 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 funds to the coup leaders.The coup was led by General Dng Vn Minh and started on 1 November 1963. It proceeded smoothly as many loyalist leaders were captured after being caught off-guard and casualties were light. Dim was captured and executed the next day along with his brother and adviser Ng nh Nhu.

The Buddhist crisis (Vietnamese: Biến cố Phật giáo) was a period of political and religious tension in South Vietnam between May and November 1963, characterized by a series of repressive acts by the South Vietnamese government and a campaign of civil resistance, led mainly by Buddhist monks.The crisis was precipitated by the shootings of nine unarmed civilians on May 8 in the central city of Huế who were protesting a ban of the Buddhist flag. The crisis ended with a coup in November 1963 by the Army of the Republic of Vietnam (ARVN), and the arrest and assassination of President Ngô Đình Diệm on November 2, 1963.