Cao 朽i is a syncretistic; monotheistic religion; officially established in the city of T鈟 Ninh; southern Vietnam; in 1926.

During the First and Second Indochina Wars; members of Cao Dai (along with several other Vietnamese sects; such as Hoa Hao) were active in political and military struggles; both against French colonial forces and Prime Minister Ng?徐nh Di?m of South Vietnam.

Their opposition to the communist forces until 1975 was a factor in their repression after the Fall of Saigon in 1975; when the incoming communist government proscribed the practice of Cao Dai. In 1995; the Thien Tien branch of Cao Dai was granted legal recognition by the government; and two years later; in 1997; the Tay Ninh Cao Dai branch was granted legal recognition.