The Catholic Apostolic Church (CAC), also known as the Irvingian Church or Irvingite Church, is a denomination in the Restorationist branch of Christianity. It originated in London around 1831 and later spread to Germany and the United States. The traditional groups of the Catholic Apostolic Church with the revisionist movement, the character of which include elements of historic liturgies and charismatic gifts are sometimes referred to as Irvingism or the Irvingian movement after Edward Irving (1792–1834), a clergyman of the Church of Scotland sometimes credited as organising the movement.

The church was organised in 1835 with the fourfold ministry of "apostles, prophets, evangelists, and pastors". The denominations in the tradition of the Catholic Apostolic Church teach "the restoration to the universal church of prophetic gifts by the direct inspiration of the Holy Ghost."

As a result of schism within the Catholic Apostolic Church, other Irvingian Christian denominations emerged, including the Old Apostolic Church, New Apostolic Church, Reformed Old Apostolic Church and United Apostolic Church; of these, the New Apostolic Church is the largest Irvingian Christian denomination today, with 16 million members.

Irvingism has elaborate liturgies; it teaches three sacraments: Baptism, Holy Communion and Holy Sealing.

Edward Irving, also a minister in the Church of Scotland, preached in his church at Regent Square in London on the speedy return of Jesus Christ and the real substance of his human nature.^{[citation needed]}

Irving's relationship to this community was, according to its members, somewhat similar to that of John the Baptist to the early Christian Church. He was the forerunner and prophet of the coming dispensation, not the founder of a new sect; and indeed the only connection which Irving seems to have had with the Catholic Apostolic Church was in fostering spiritual persons who had been driven out of other congregations for the exercise of their spiritual gifts.

Around him, as well as around other congregations of different origins, coalesced persons who had been driven out of other churches, wanting to "exercise their spiritual gifts". Shortly after Irving's trial and deposition (1831), he restarted meetings in a hired hall in London, and much of his original congregation followed him. Having been expelled from the Church of Scotland, Irving took to preaching in the open air in Islington, until a new church was built for him and his followers in Duncan Street, Islington, funded by Duncan Mackenzie of Barnsbury, a former elder of Irving's London church.

Shortly after Irving's trial and deposition (1831), certain persons were, at some meetings held for prayer, designated as "called to be apostles of the Lord" by certain others claiming prophetic gifts.