Approximately 90 per cent of the Cambodian population follows Therevada or Hinayana Buddhism, though this is strongly overlaid with ancestor-worship and animist practices.

Over the centuries Buddhist temples (wats) developed an important role in the preservation of culture and the provision of education, especially in rural areas.

However, during the 1970s Buddhists were severely persecuted by the Khmer Rouge. Monks were forced to do manual labour with the rest of the population and many lost their lives; most of the country’s wats were destroyed during this period. Since the 1980s, with the encouragement of the government, Buddhism has undergone a remarkable revival and is now recognised in the Cambodian Constitution as the state religion.

The Cambodian Buddhist sangha is divided into two distinct sects. Based at Phnom Penh's Wat Ounalom, the larger Mahanikaya sect accounts for some 90 per cent of the clergy; the head of this order is widely recognised as the leader of the Cambodian Buddhist sangha. The smaller Thammayut (royalist) Buddhist sect was introduced from Thailand in 1864 and gained prestige because of its adoption by royalty and aristocracy; it is based at Phnom Penh's Wat Botum.

The Islamic faith is practiced by the Cham-Muslim communities of the south east. Like the Buddhists, Cambodia’s Muslim community also experienced persecution at the hands of the Khmer Rouge and many were killed. There are currently estimated to be around 250 mosques in the country, 90 of which are in Kompong Cham Province.

Christianity accounts for a small but growing community in Phnom Penh and other urban areas. Animism continues to be the dominant faith amongst the hill tribes.