A schism ( /ˈskɪzəm/ or /ˈsɪzəm/; Greek: σχίσμα, skhísma, from σχίζω, skhízō, "to tear, to split") is a division between people, usually belonging to an organization or movement religious denomination. The word is most frequently applied to a break of communion between two sections of Christianity that were previously a single body, or to a division within some other religion. It is also used of a split within a non-religious organization or movement or, more broadly, of a separation between two or more people, be it brothers, friends, lovers, etc.

A schismatic is a person who creates or incites schism in an organization or who is a member of a splinter group. Schismatic as an adjective means pertaining to a schism or schisms, or to those ideas, policies, etc. that are thought to lead towards or promote schism.

In religion, the charge of schism is distinguished from that of heresy, since the offence of schism concerns not differences of belief or doctrine but promotion of, or the state of, division, but schisms frequently involve mutual accusations of heresy. In Roman Catholic teaching, every heresy is a schism. However, the Presbyterian scholar James I. McCord (quoted with approval by the Episcopalian bishop of Virginia Peter Lee) drew a distinction between them, teaching: "If you must make a choice between heresy and schism, always choose heresy. As a schismatic, you have torn and divided the body of Christ. Choose heresy every time."

Schism may refer to:

Religion is a collection of cultural systems, belief systems, and worldviews that relate humanity to spirituality and, sometimes, to moral values. Many religions have narratives, symbols, traditions and sacred histories that are intended to give meaning to life or to explain the origin of life or the universe. They tend to derive morality, ethics, religious laws or a preferred lifestyle from their ideas about the cosmos and human nature.

The word religion is sometimes used interchangeably with faith or belief system, but religion differs from private belief in that it has a public aspect^{[citation needed]}. Many religions have organized behaviors, clergy, a definition of what constitutes adherence or membership, congregations of laity, regular meetings or services for the purposes of veneration of a deity or for prayer, holy places (either natural or architectural), and/or scriptures. The practice of a religion may also include sermons, commemoration of the activities of a god or gods, sacrifices, festivals, feasts, trance, initiations, funerary services, matrimonial services, meditation, music, art, dance, public service, or other aspects of human culture. However, there are examples of religions for which some or many of these aspects of structure, belief, or practices are absent.