Filipino shamans, commonly known as babaylan (also balian or katalonan, among many other names), were shamans of the various ethnic groups of the pre-colonial Philippine islands. These shamans specialized in communicating, appeasing, or harnessing the spirits of the dead and the spirits of nature. Babaylan were predominantly women serving in spiritual leadership roles; in rare instances, effeminate men (asog or bayok) adopted dress and roles commonly associated with women within indigenous spiritual practice. They were believed to have spirit guides, by which they could contact and interact with the spirits and deities (anito or diwata) and the spirit world. Their primary role were as mediums during pag-anito séance rituals. There were also various subtypes of babaylan specializing in the arts of healing and herbalism, divination, and sorcery.

The most common native terms for shamans among Austronesian groups in Island Southeast Asia are balian, baylan, or cognates and spelling variants thereof. They are all derived from Proto-Western-Malayo-Polynesian *balian, meaning "shaman" (probably originally female, transvestite, or hermaphroditic) or "medium". Various cognates in other non-Filipino Austronesian languages include babalian, bobolian, and bobohizan (Kadazan-Dusun); wadian (Ma'anyan); belian (Iban); belian (Malay); walen or walyan (Old Javanese); balian (Balinese); bolian (Mongondow); balia (Uma); wulia or balia (Bare'e); balia (Wolio); balian (Ngaju); and balieng (Makassar). However *balian-derived terms have largely disappeared among lowland Filipinos after Christianization in the Spanish era. Some exceptions include Bikol where it persisted and acquired the Spanish feminine suffix -a as balyana. It also survives among some Muslim Filipinos like in Maranao walian, although the meaning has shifted after Islamization.

The linguist Otto Dempwolff has also theorized that *balian may have ultimately derived from Proto-Austronesian *bali ("escort", "accompany") with the suffix *-an, in the meaning of "one who escorts a soul to the other world (a psychopomp)". However, the linguists Robert Blust and Stephen Trussel have noted that there is no evidence that *balian is a suffixed form, and thus believe that Dempwolff's interpretation is incorrect.

More general terms used by Spanish sources for native shamans throughout the archipelago were derived from Tagalog and Visayan anito ("spirit"), these include terms like maganito and anitera. However, different ethnic groups had different names for shamans, including shamans with specialized roles. These include:

According to Jaime Veneracion, Katalonan incorporates the root talon which in ancient Tagalog meant "forest" (cf. Hiligaynon, Masbatenyo, Inabaknon, Capisano, Palawano, Buhid, and Agutaynen talon, "forest" or "thicket"). Other scholars believed that the origin of the word catalonan is from its root word "talo" which according to them is a Tagalog word originally means "to converse", thus the word catalonan literally means someone who converse or communicate with the spirits (anito). According to Blumentritt an old Tagalog word "tarotaro" is a term describing the catalonas while possessed by the spirits (anito). In some Malayo-Polynesian languages such as Tahitian "tarotaro" means 'to pray', while in Rapanui it means 'a malediction or curse'. In Samoan "talo or talotalo" means 'a prayer or to pray'.^{[citation needed]} Linguist Malcolm Mintz, however, offers a different etymology. He determines that the Tagalog root word is "tulong" which means to help. Some writers such as William Henry Scott and Luciano P. R. Santiago favoured Mintz suggestion and used the term catolonan (which is actually a Pampangan term) to refer to the priests and priestesses of the Tagalogs instead of catalona or catalonan.

Most babaylan inherited their status from an older babaylan they were apprenticed to, usually a relative. In some cultures, like among the Isneg people, older shamans can choose apprentices from among the eligible young women of the village.

A few, however, become babaylan after experiencing what has been termed a "shamanistic initiatory crisis" (also "shamanic illness" or "shamanic madness"). This includes serious or chronic illnesses, near-death experiences, sudden seizures and trembling, depression, strange events or behavior (including climbing balete trees or disappearing for several days with no memory of the events), bouts of insanity (including those induced by psychological trauma from a past event), and strange visions or dreams. These are regarded as encounters with the spirits, where the soul of the person is said to be journeying to the spirit world. In cases like this, it is said that a spirit chose the person, rather than the other way around.

After being chosen, shamans go through an initiation rite. These rites are meant to gain or transfer the patronage of a spirit. Among Visayans, this ritual is known as the tupad or tupadan. In cases of people with "shamanic illness", these initiation rites are regarded as the cure, where the initiate regains health or sanity by conceding to the wishes of the spirits and "answering the call". When volunteered rather than volunteering, their relatives are usually required to pay a large fee to the senior shaman for the training. Initiation rites can range from simply inducing a trance through herbs or alcohol, to inducing personal crises through physical or psychological hardship. Extreme examples of initiation rites include getting buried alive or being immersed in water overnight.