Orishas (singular: orisha) are divine spirits that play a key role in the Yoruba religion of West Africa and several religions of the African diaspora that derive from it, such as Haitian Vaudou, Cuban Santería and Brazilian Candomblé. The preferred spelling varies depending on the language in question: òrìṣà is the spelling in the Yoruba language, orixá in Portuguese, and orisha, oricha, orichá or orixá in Spanish-speaking countries. In the Lucumí tradition, which evolved in Cuba, the orishas are synchronized with Catholic saints, forming a syncretic system of worship where African deities are hidden behind Christian iconography. This allowed enslaved Africans to preserve their traditions under colonial religious persecution.

According to the teachings of these religions, the orishas are spirits sent by the supreme creator, Olodumare, to assist humanity and to teach them to be successful on Ayé (Earth). Rooted in the native religion of the Yoruba people, most orishas are said to have previously existed in òrún—the spirit world—and then became Irúnmọlẹ̀—spirits or divine beings incarnated as human on Earth. Irunmole took upon a human identity and lived as ordinary humans in the physical world, but because they had their origin in the divine, they had great wisdom and power at the moment of their creation.

The orishas found their way to most of the New World as a result of the Atlantic slave trade and are now expressed in practices as varied as Haitian Vodou, Santería, Candomblé, Trinidad Orisha, Umbanda, and Oyotunji, among others. The concept of òrìṣà is similar to those of deities in the traditional religions of the Bini people of Edo State in southern Nigeria, the Ewe people of Benin, Ghana, and Togo, and the Fon people of Benin.

In diaspora communities, the worship of Orishas often incorporates drumming, dance, and spirit possession as central aspects of ritual life. These practices serve to strengthen communal bonds and foster direct spiritual experiences among practitioners.

Yoruba tradition often says that there are 400 + 1 orishas, which is associated with a sacred number. Other sources suggest that the number is "as many as you can think of, plus one more – an innumerable number". Different oral traditions refer to 400, 700, or 1,440 orishas.This symbolic numbering system reflects the complexity and vastness of the spiritual world in Yoruba cosmology. The phrase "400 + 1" represents the idea that the divine world cannot be fully quantified or comprehended by human minds.

Practitioners traditionally believe that daily life depends on proper alignment and knowledge of one's Orí. Ori literally means the head, but in spiritual matters, it is taken to mean a portion of the soul that determines personal destiny.

Offerings, prayers, and self-reflection are all means by which a devotee can align with their Orí, thereby ensuring balance, success, and fulfillment in life. Without proper alignment with one's Orí, even the assistance of the orishas may prove ineffective.

Some orishas are rooted in ancestor worship; warriors, kings, and founders of cities were celebrated after death and joined the pantheon of Yoruba deities. The ancestors did not die but were seen to have "disappeared" and become orishas. Some orishas based on historical figures are confined to worship in their families or towns of origin; others are venerated across wider geographic areas.