Kejawèn (Javanese: ꦏꦗꦮꦺꦤ꧀, romanized: Kajawèn) or Javanism, also known as Kebatinan, Agama Jawa lit. 'Javanese Religion', and Kepercayaan lit. 'Belief', is a Javanese cultural tradition, consisting of an amalgam of animistic, Buddhist, Hindu and Islamic aspects. It is rooted in Javanese history and religiosity, syncretizing aspects of different religions and traditions.

The term kebatinan is being used interchangeably with kejawèn, Agama Jawa and Kepercayaan, although they are not exactly the same:

Kebatinan is the inward cultivation of inner peace, rooted in pre-Islamic traditions, whereas kejawèn is outward and community-oriented, manifesting in rituals and practices.

Java has been a melting pot of religions and cultures, which has created a broad range of religious beliefs, including animism, spirit cults, and cosmology.

Indian influences came firstly in the form of Hinduism, which reached the Indonesian Archipelago as early as the first century. By the fourth century, the kingdom of Kutai in East Kalimantan, Tarumanagara in West Java, and Holing (Kalingga) in Central Java, were among the early Hindu states established in the region. Several notable ancient Indonesian Hindu kingdoms are: Mataram, famous for the construction of the majestic Prambanan temple, followed by Kediri and Singhasari. Since then, Hinduism, along with Buddhism, spread across the archipelago and reached the peak of its influence in the fourteenth century. The last and largest of the Hindu-Buddhist Javanese empires, that of the Majapahit, influenced the entire Indonesian archipelago.^{[citation needed]}

Hinduism and Buddhism penetrated deeply into all aspects of society, blending with the indigenous tradition and culture. One conduit for this was the ascetics, called "resi," (Sanskrit rishi) who taught a variety of mystical practices. A resi lived surrounded by students, who took care of their master's daily needs. Resi's authorities were merely ceremonial. At the courts, Brahmanas clerics and pudjangga (sacred literati) legitimized rulers and linked Hindu cosmology to their political needs. Presently, small Hindu enclaves are scattered throughout Java, but there is a large Hindu population along the eastern coast nearest Bali, especially around the town of Banyuwangi.

Java adopted Islam around 1500 CE. Islam was first accepted by the elites and upper echelons of society, which contributed to its further spread and acceptance. Sufism and other versions of Folk Islam were most easily integrated into the existing folk religion of Java. The learned versions of Sufi Islam and Shari`a-oriented Islam were integrated at the courts, blending with the rituals and myths of the existing Hindu-Buddhist culture. Clifford Geertz described this as abangan and priyayi; "the lower class and elite varieties of Javanese syncretism".

The Kyai, the Muslim scholar of the writ, became the new religious elite as Hindu influences receded. Islam recognises no hierarchy of religious leaders nor a formal priesthood, but the Dutch colonial government established an elaborate rank order for the mosque and other Islamic preaching schools. In Javanese pesantren (Islamic schools), The Kyai perpetuated the tradition of the resi. Students around him provided his needs, even peasants around the school.