Mahayana Buddhism is the largest religion in Vietnam. There is a significant minority of Catholic Christians. Other religions include Protestant Christianity, Theravada Buddhism, Islam, Hòa Hảo, and the syncretic Cao Đài religion. Many citizens consider themselves non-religious, although they may practice traditional beliefs such as veneration of ancestors and national heroes. Ethnic minorities historically practice different traditional beliefs than those of the ethnic majority Kinh. Many ethnic minorities, particularly among the H'mong, Zao, and Jarai groups in the Northwest and Central Highlands, have converted to Protestantism.
Undeclared missionaries from several countries are active in the country. Foreign missionaries legally are not permitted to proselytize or perform religious activities.