Vietnam is located in Southeast Asia and the country has a large population. Vietnam’s population would reach to 100 million people ranked 15th in the world[1]. Vietnam has undergone significant changes throughout its history, reflecting the country's complex socio-political landscape. The Vietnamese society is complex and the region is no exception. Vietnam has a rich religious heritage, influenced by Buddhism, Confucianism, and Taoism. However, the introduction of foreign religions, such as Catholicism and Protestantism, during the colonial era brought new dynamics to Vietnam’s religious landscape. The French colonization period saw tensions between the Catholic Church and the Vietnamese government, which continued even after Vietnam gained independence. After the Vietnamese war finished, Vietnam also saw tensions between unregistered groups such as Hoa Hao Buddhist community and the Vietnamese authorities and its continuous crackdown on unregistered groups. This paper aims to provide an overview of Vietnam's religion, and highlight key and recent developments, policies, key challenges for some religions such as Pure Hoa Hao Buddhism, the Vietnamese government has restricted on unregistered groups, the current state of religious freedom in the country.