Animal worship (or zoolatry) is an umbrella term designating religious or ritual practices involving animals. This includes the worship of animal deities or animal sacrifice. An animal 'cult' is formed when a species is taken to represent a religious figure (Teeter et al., 2002, p. 355). Animal cults can be classified according to their formal features or by their symbolic content (Thomas 1911, p. 51).

The classical author Diodorus situated the origin of animal worship in a myth in which the gods, threatened by giants, disguised themselves as animals. The people then began to worship these animals and continued even after the gods returned to their normal state (Lubbock, 2005, p. 252). In 1906, Weissenborn suggested that animal worship resulted from humans' fascination with the natural world. Primitive man would observe an animal that had a unique trait and the inexplicability would engender curiosity (Weissenborn, 1906b, p. 282). Wonder resulted from primitive man's observations of this distinctive trait. As such, primitive man worshipped animals that had inimitable traits (Weissenborn, 1906b, p. 282). Lubbock proposed that animal worship originated from family names. In societies, families would name themselves and their children after certain animals and eventually came to hold that animal above other animals. Eventually, these opinions turned into deep respect and evolved into fully developed worship of the family animal (Lubbock, 1870, p. 253). The belief that an animal is sacred frequently results in dietary laws prohibiting their consumption. As well as holding certain animals to be sacred, religions have also adopted the opposite attitude, that certain animals are unclean.

The idea that divinity embodies itself in animals, such as a deity incarnate, and then lives on earth among human beings is disregarded by Abrahamic religions (Morris, 2000, p. 26). Sects deemed heretical such as the Waldensians were accused of animal worship. In Independent Assemblies of God and Pentecostal churches, animals have very little religious significance (Schoffeleers, 1985; Peltzer, 1987; Qtd. in Morris, 2000, p. 25). Animals have become less and less important and symbolic in cult rituals and religion, especially among African cultures, as Christianity and Islamic religions have spread. (Morris, 2000, p. 24).

The Egyptian pantheon was especially fond of zoomorphism, with many animals sacred to particular deities—cats to Bastet, ibises and baboons to Thoth, crocodiles to Sobek and Ra, fish to Set, mongoose, shrew and birds to Horus, dogs and jackals to Anubis, serpents and eels to Atum, beetles to Khepera, bulls to Apis. Animals were often mummified as a result of these beliefs. In Wicca, the Horned God represents an animal-human deity.