Congregational churches are Protestant Christian churches practicing Congregationalist church governance, in which each congregation independently and autonomously runs its own affairs.

Many Congregational churches claim their descent from a family of Protestant denominations formed on a theory of union published by the theologian Robert Browne in 1592. These arose from the Nonconformist religious movement during the Puritan reformation of the Church of England. In Great Britain, the early congregationalists were called separatists or independents to distinguish them from the similarly Calvinistic Presbyterians. Some congregationalists in Britain still call themselves Independent.

Congregational churches were widely established in the Massachusetts Bay Colony, later New England. The model of Congregational churches was carried by migrating settlers from New England into New York and the Old Northwest regions that now includes Ohio, Indiana, Michigan and Illinois. With their insistence on independent local bodies, they became important in many social reform movements, including Abolitionism and women's suffrage. Modern congregationalism in the U.S. is split into three bodies: the United Church of Christ, which most local Congregational churches affiliate with; the National Association of Congregational Christian Churches; and the Conservative Congregational Christian Conference, an evangelical group.