Cao Dai pronunciation  (Cao Đài) is a relatively new, syncretist, monotheistic religion, officially established in Tây Ninh, southern Vietnam, in 1926. Đạo Cao Đài is the religion's shortened name, the full name is Đại Đạo Tam Kỳ Phổ Độ (Great Religion [of The] Third Period [of] Revelation [and] Salvation). The term Cao Đài literally means "high place." Figuratively, it means that highest place where God reigns. It is also the abbreviated name for God, the creator of the universe, whose full title is Cao Đài Tiên Ông Đại Bồ Tát Ma-ha-tát.

Caodaiists credit God as the religion's founder. They believe the teachings, symbolism and organization were communicated directly from Đức (means Venerable) Cao Đài. Even the construction of the Tây Ninh Holy See is claimed to have had divine guidance. Cao Đài's first disciples Ngô Văn Chiêu, Cao Quỳnh Cư, Phạm Công Tắc, and Cao Hoài Sang claimed to have received direct communications from God, who gave them explicit instructions for establishing a new religion that would commence the Third Era of Religious Amnesty.

Adherents engage in ethical practices such as prayer, veneration of ancestors, nonviolence, and vegetarianism with the minimum goal of rejoining God the Father in Heaven and the ultimate goal of freedom from the cycle of birth and death. Estimates of the number of Cao Đài adherents in Vietnam vary, but most sources give two to three million. Some estimates are as high as eight million adherents in Vietnam. An additional 30,000 (primarily ethnic Vietnamese) in the United States, Europe, and Australia.