Satanism is a group of ideological and philosophical beliefs based on Satan. Contemporary religious practice of Satanism began with the founding of the Church of Satan in 1966, although a few historical precedents exist. Prior to the public practice, Satanism existed primarily as an accusation by various Christian groups toward perceived ideological opponents, rather than a self-identity. Satanism, and the concept of Satan, has also been used by artists and entertainers for symbolic expression.

Accusations that various groups have been practicing Satanism have been made throughout much of Christian history. During the Middle Ages, the Inquisition attached to 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 mass trials of alleged witches across Europe and the North American colonies. Accusations that Satanic conspiracies were active, and behind events such as Protestantism (and conversely, the Protestant claim that the Pope was the Antichrist) and the French Revolution continued to be made in Christendom during the eighteenth to the twentieth century. The idea of a vast Satanic conspiracy reached new heights with the influential Taxil hoax of France in the 1890s, which claimed that Freemasonry worshiped Satan, Lucifer, and Baphomet in their rituals. In the 1980s and 1990s, the Satanic ritual abuse hysteria spread through the United States and the United Kingdom, amid fears that groups of Satanists were regularly sexually abusing and murdering children in their rites. In most of these cases, there is no corroborating evidence that any of those accused of Satanism were actually practitioners of a Satanic religion or guilty of the allegations leveled at them.

In their study of Satanism, the religious studies scholars Asbjørn Dyrendal, James R. Lewis, and Jesper Aa. Petersen stated that the term Satanism "has a history of being a designation made by people against those whom they dislike; it is a term used for 'othering'".[5] The concept of Satanism is an invention of Christianity, for it relies upon the figure of Satan, a character deriving from Christian mythology.