structural:expansion, information:filtering
Satanism refers to a group of religious, ideological, and/or philosophical beliefs based on Satan – particularly his worship or veneration. Satan is commonly associated with the Devil in Christianity, a fallen angel often regarded as chief of the demons who tempt humans into sin. The phenomenon of Satanism shares "historical connections and family resemblances" with the Left Hand Path milieu of other occult figures such as Chaos, Hecate, Lilith, Lucifer, and Set. For centuries, the term was used by various Christian groups as an accusation against ideological opponents, a slur for assorted heretics, freethinkers, and pagans. By contrast, self-identified Satanism is a relatively modern phenomenon, largely attributed to the 1966 founding of the Church of Satan by Anton LaVey in the United States – an atheistic group that does not believe in a supernatural Satan.

Accusations of groups engaged in " devil worship " have echoed throughout much of Christian history. During the Middle Ages, the Inquisition led by the Catholic Church alleged that various heretical Christian sects and groups, such as the Knights Templar and the Cathars, performed secret Satanic rituals. In the subsequent Early Modern period, belief in a widespread Satanic conspiracy of witches resulted in the trials and executions of tens of thousands of alleged witches across Europe and the North American colonies, peaking between 1560–1630 CE. The terms "Satanist" and "Satanism" emerged during the Reformation and Counter-Reformation (1517–1700 CE), as both Catholics and Protestants accused each other of intentionally being in league with Satan. Accusations of Satanism made during the 18th to 20th centuries include being the cause of the French Revolution of 1789, the evil force behind Freemasonry, and an unfounded moral panic in the United States and the United Kingdom during the 1980s and '90s.

Since the 19th century, various small religious groups have emerged that identify as Satanist or use Satanic iconography. While the groups that appeared after the 1960s differed greatly, they can be broadly divided into theistic Satanism and atheistic Satanism. Those venerating Satan as a supernatural deity are unlikely to ascribe omnipotence, instead relating to Satan as a patriarch. Atheistic Satanists regard Satan as a symbol of certain human traits, a useful metaphor without ontological reality. Contemporary religious Satanism is predominantly an American phenomenon, though the rise of globalization and the Internet have seen these ideas spread to other parts of the world.