Although only about half of the people of Vietnam belong to organized religions, religion, and the beliefs arising from religions play large parts in the lives of most Vietnamese. They are often very superstitious, and believe things must be done right, or the family will have bad luck. Most Vietnamese practice ancestor worship. They believe that the spirits of their ancestors come back to earth on specific days, and throughout the year they pay high respect to them. In many homes there is a small alter to the ancestors of the family where they burn incense, have food offerings, and pictures of their deceased family members. Certain beliefs of many religions such as Buddhism, Taoism, Confucianism, animism and Catholicism are incorporated into the lives of the everyday, not seriously religious, Vietnamese person.

Of the people who are members of organized religions, the greatest number are Buddhists. Buddhism came to Vietnam from India, during the Chines rule. This religion concentrates on self improvement and the belief of more lives after death. People must carry themselves well and improve and realize themselves in this life in order to pass on to a better life in their next one. There are slightly different beliefs between the north and south. The members of the Hoa Hao sect in South Vietnam are more radical in their beliefs than members of the more passive sects in the north. Hoa Hao is the largest major sect of Vietnamese Buddhism, was founded during the early 20th century in South Vietnam, and has over one million followers.

Catholicism is another major religion. It was brought to Vietnam by the French colonists and has about four million followers. Many Catholics were against communism, and many fled the country when it was split up in 1954 and when it was reunited in 1975. Other Christian churches have sent missionaries to Vietnam, but were not widely adopted.

Many of the mountain tribes practice spirit worship, or Animism. There are differences between what each tribe believes. In general, Animism is an ancient religion centered on the belief that clouds, rivers, forests, animals, etc. all have spirits. It used to be believed all over the world, but now only in scattered regions, including the Vietnamese highlands.

Confucianism is more of a philosophy than a religion, but it has a strong influence on Vietnamese life. The Vietnamese took many of the Confucian morals and ethics. Confucianism, introduced by the Chinese, teaches respect, honest government, formality, and that people should be rewarded for merit. Another Chinese religion that influences Vietnamese philosophy today is Taoism. A few of the teachings of Taoism are belief in the spirit world, and the importance of how things line up. People must be very careful where they build houses, dig graves, or face doors, or it could be very unlucky.

Perhaps the strangest Vietnamese religion is Cao Dai. It was founded in 1919 in the city of Tay Ninh and has as many as one million followers today. Cao Dai was established to 'bring together the best of all religions.' There are little bits and pieces of many religions as part of it. Among its saints are religious figures from other faiths as well as famous people from history such as author Victor Hugo, and comedian Charlie Chaplain . They have statues and icons that are mixtures of important Vietnamese mythical animals, and things found in other religions, with a little bit of their own innovation included.

Many seriously religious people are activists. They believe in justice for all, and the government may not completely trust their loyalty, so it discourages strong devotion to some religions. Vietnam's diversity of people and religions throughout history has helped make Vietnam the fascinating country that it is today.