Anglicanism is a tradition of Christian faith. Churches in this tradition either have historical connections to the Church of England or have similar beliefs, worship and church structures. The word Anglican originates in ecclesia anglicana, a medieval Latin phrase dating to at least 1246 meaning the English Church. Adherents of Anglicanism are called Anglicans. The great majority of Anglicans are members of churches which are part of the international Anglican Communion. There are, however, a number of churches outside of the Anglican Communion which also consider themselves to be in the Anglican tradition, most notably those referred to as Continuing Anglican churches.

The faith of Anglicans is founded in the scriptures, the traditions of the apostolic church, the apostolic succession—"historic episcopate" and the early Church Fathers. Anglicanism forms one of the branches of Western Christianity; having definitively declared its independence from the Roman pontiff at the time of the Elizabethan Religious Settlement. By the mid 17th century the Church of England (and associated episcopal churches in Ireland and in England's American colonies) came to be seen as comprising a distinct Christian tradition with theologies, structures and forms of worship representing a middle ground, or via media, between Roman Catholicism and Protestantism. Following the American Revolution, Anglican congregations in the United States and Canada were each reconstituted into an independent church with their own bishops and self-governing structures; which, through the expansion of the British Empire and the activity of Christian missions, was adopted as the model for many newly formed churches, especially in Africa, Australasia and the regions of the Pacific. In the 19th century the term Anglicanism was coined to describe the common religious tradition of these churches; as also that of the Scottish Episcopal Church, which, though originating earlier within the Church of Scotland, had come to be recognised as sharing this common identity.

The degree of distinction between Reformed and western Catholic tendencies within the Anglican tradition is routinely a matter of debate both within specific Anglican churches and throughout the Anglican Communion. Unique to Anglicanism is the Book of Common Prayer, the collection of services that worshippers in most Anglican churches used for centuries. While it has since undergone many revisions and Anglican churches in different countries have developed other service books, the Prayer Book is still acknowledged as one of the ties that bind the Anglican Communion together. There is no single Anglican Church with universal juridical authority, since each national or regional church has full autonomy. As the name suggests, the Anglican Communion is an association of those churches in full communion with the Archbishop of Canterbury.The Oxford Dictionary of the Christian Church by F. L. Cross (Editor), E. A. Livingstone (Editor) Oxford University Press, USA; 3 edition p.65 (March 13, 1997) With over seventy-seven million members the Anglican Communion is the third largest Christian communion in the world, after the Roman Catholic Church and the Eastern Orthodox Church.