Kaharingan is an indigenous animistic folk religion of the Dayak people such as Katingan, Lawangan, Ma'anyan, Ngaju, Ot Danum, and Meratus peoples, native to the provinces of Central Kalimantan and South Kalimantan in Indonesia.

The word means something like Way of the life, and this belief system includes a concept of many deities and often one supreme deity—although this may be the result of the need to conform to the idea of "One Supreme God" (Ketuhanan yang Maha Esa), which is the first principle of the Indonesian state ideology Pancasila. The influence of Hinduism can also be seen in this religion. Before 2017, the Indonesian government viewed it as a form of Folk Hinduism because the Indonesian government at that time recognized only six official religions, and Kaharingan was not one of them. However, since November 2017, the government started to formally recognize Aliran Kepercayaan, a broadly defined group of native religions, which also includes Kaharingan.

The main festival of Kaharingan is the Tiwah festival, which lasts for thirty days, and involves the sacrifice of many animals like buffaloes, cows, pigs and chickens, as offerings to the spirits and deities.

The religion has ritual offerings called Yadnya, places of worship called Balai Basarah or Balai Kaharingan and a holy book called Panaturan, Talatah Basarah (group of prayers) and Tawar (a guide to seek God's help by giving rice). Ancestor worship and the belief in many supernatural beings is common.

Kaharingan comes from the Old Dayak word haring meaning "life" or "alive". This concept is expressed in the symbol of the faith depicting a kind of Tree of Life called Batang Garing. This Tree of Life somewhat resembles a spear that has three branches on either side, some facing up and some down. At the bottom of the symbol are two receptacles, while at the very top are a hornbill and the sun.

The spear and its branches denote the upper world and the afterlife (spirit world), while the lower receptacles convey the idea of man's earthly life. Although both the spiritual world and the earthly world are different, but they are closely connected to one another and are inseparable since they are both interdependent. The branches, where some face up while others face down, mean that there is an eternal balance between the earthly and the afterlife. That life on earth is temporary, and that human life is designed for the hereafter.

Altogether the Tree of Life expresses the core of the Kaharingan faith, which is that human life must be balanced and kept in harmony between man and spirits and between man and his natural environment. This is also the basic concept of Balinese Hinduism, which in Bali is known as the Tri Hita Karana.

In practice the Ngaju Dayaks focus on the supernatural world of spirits, including ancestral spirit. For them, the secondary funeral is most important, usually held after several months or even years after burial. During the second funeral rites (known as tiwah) the bones are exhumed and cleansed then placed in a special mausoleum, called sandung. The spirit of the deceased is then believed to watch over the village. The mausoleums are often beautifully decorated, showing scenes of the upper world. An ornate ship of the dead made of rubber is usually placed next to the remains depicting his entourage that accompany the soul to paradise.