Cao ??i is a syncretistic, monotheistic religion, officially established in the city of T璽y 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繫 ?穫nh Di廙?? 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.