Cambodian Buddhism rests on a Theravāda foundation that was laid down after earlier layers of religious life had already taken shape. Indian influence first brought Hinduism and forms of Buddhism into the early Khmer polities, where royal Hindu cults and Mahāyāna Buddhism coexisted with local practices. From roughly the 13th to 15th centuries, Theravāda lineages associated with Sri Lanka, transmitted through neighboring Mon and Thai regions, gradually became dominant. This shift did not simply replace what came before; it reoriented the religious landscape so that Pāli canon–based teachings, the monastic saṅgha, and the ideal of the righteous Buddhist ruler became central, while older forms were reinterpreted rather than erased.

The integration of pre-Buddhist beliefs can be seen most vividly in the way animistic and ancestral cults were woven into a Buddhist worldview. Local guardian and land spirits, often referred to as neak ta, continued to be honored as protectors of particular places and communities, yet were subtly subordinated within a broader Buddhist cosmology. Ancestor veneration and fertility rites associated with rice agriculture, land, and water persisted, but were increasingly expressed through Buddhist merit-making: offerings to monks and ritual acts were dedicated to deceased relatives, linking karmic ideas with older notions of ancestral blessing. In village life, shrines to spirits stand alongside monasteries, and ceremonies may involve both Buddhist chanting and traditional gestures toward nature and territorial powers.

Elements inherited from the Hindu and Mahāyāna past were also absorbed into this evolving Theravāda framework. Deities such as Śiva, Viṣṇu, and Brahmā, once central to royal cults, came to be regarded as powerful devas or protector figures within a Buddhist universe, rather than as supreme gods. Older temples and images, whether originally Hindu or Mahāyāna, were often recontextualized as Buddhist sacred sites, their earlier sectarian meanings overshadowed by a more encompassing devotional sensibility. The royal ideology itself shifted from the explicitly divine kingship of earlier eras toward the model of the dhammarāja, the ruler whose legitimacy rests on upholding the Dhamma, yet still bearing a sacral connection to the well-being of the land.

At the level of everyday practice, this synthesis produced what is often described as a “folk” expression of Theravāda. Traditional healers and ritual specialists continued to employ amulets, divination, and protective magic, but increasingly framed their work with Buddhist mantras, yantras, and blessings from monks. Monastics, for their part, came to preside not only over canonical rites but also over life-cycle ceremonies, agricultural blessings, and communal festivals that retain unmistakable pre-Buddhist motifs. The result is a religious culture in which canonical doctrine and local spirituality are not experienced as rivals, but as interlocking layers: the Dhamma provides the overarching meaning, while spirits, ancestors, and deities inhabit a shared sacred cosmos ordered, but not annihilated, by Buddhist insight.