Mapuche religion is the traditional Native American religion of the Mapuche people. It is practiced primarily in south-central Chile and southwest Argentina. The tradition has no formal leadership or organizational structure and displays much internal variation.

Mapuche theology incorporates a range of deities and spirits. One of the most prominent deities is Ngünechen, sometimes equated with the Christian God. Communal prayer ceremonies are termed ngillatun and involve the provision of offerings and animal sacrifice. Various different ritual specialists were historically active among the Mapuche, but in the 20th century many of these died out, leaving the machi as the main kind. These machi are tasked with overseeing healing and divination, tasks accomplished through their communication with spirits.

Historically, the Mapuche were politically independent and prevented conquest by the Incan and Spanish Empires. In 1883 the Chilean military defeated the Mapuche and began to restrict them to reservations. Chilean efforts were then made to convert the Mapuche to Catholicism. From the 1990s, Mapuche religion underwent a revitalisation, with greater visibility and efforts to use it to encourage tourism.

Mapuche religion is not institutional. In Latin America, traditional religions are rarely pure, unadulterated continuations from the traditions that existed prior to European contact. The term "Mapuche," found in the Mapuche language, means "people of the land". Another term for this people, used by the Spanish colonialists, was the Araucanians. Contemporary Mapuche people are largely bilingual, speaking both their own language, Mapudungan, and Spanish, the main colonial language of the region.

In order to describe the beliefs of the Mapuche people, it is important to note that there are no written records about their ancient legends and myths from before the Spanish arrival, since their religious beliefs were passed down orally. Their beliefs are not necessarily homogenous; among different ethnic groups, and the families, villages, and territorial groups within those ethnic groups, there are variations and differences and discrepancies in these beliefs. Likewise, it is important to understand that many of the Mapuche beliefs have been integrated into the myths and legends of Chilean folklore, and to a lesser extent, folklore in some areas of Argentina. Many of these beliefs have been altered and influenced by Christianity, due largely to the evangelization done by Spanish missionaries. This happened chiefly through the syncretism of these beliefs and also through misinterpretation or adaptation within both Chilean and Argentine societies. This syncretism has brought about several variations and differences of these core beliefs as they have become assimilated within Chilean, Argentine and even Mapuche culture. Today, these cultural values, beliefs and practices are still taught in some places with an aim to preserve different aspects of this indigenous Mapuche culture.

Mapuche traditional religion features a pantheon of gods and goddesses. The Meli Küyen are the four moon spirits; the Meli Wangülen are the four spirits of the stars. The wenu püllüam are ancestral spirits in the sky.

Ngünechen is also known as Chaw Dios (Old Man God) and Ñuke Dios (Old Woman God). Ngünechen first appeared in Mapuche religion during the 19th century; it has been argued that the introduction of this deity was a response to the Chilean national hierarchies. The root of this divinity's name, genche, first appeared in 1601 to describe a Spanish landowner. Many Mapuche equate Ngünechen with the Christian God, although other Mapuche traditionalists stress they are different.

The ngen are nature spirits. They populate the earth and are in turn prayed to by other spirits. These ngen are the owners of particular environments and can capture, possess, and punish those who enter their realms without permission. The foki spirits are intermediaries between the forest and humanity, connecting the two through the rainbow. Like humans, the foki engage in prayer.