Tay Ninh is a provincial city in southwestern Vietnam. It is the capital of Tay Ninh Province, which encompasses the town and much of the surrounding farmland. Tây Ninh is approximately 90 km to the northwest of Ho Chi Minh City, Vietnam's largest city. As of 2013, the city had a population of 153,537, and a total area of 140 km².

The city is most famous for being the home of the Cao Dai religion, an indigenous Vietnamese faith that includes the teachings of the major world religions. The Cao Dai religion's Holy See, built between 1933 and 1955, is located around 5 km to the east of Tây Ninh's city centre.