Week of Prayer for Christian Unity

The Week of Prayer for Christian Unity is an ecumenical Christian observance in the Christian calendar that is celebrated internationally. It is kept annually between Ascension Day and Pentecost in the Southern Hemisphere and between 18 January and 25 January in the Northern Hemisphere. It is an octave, that is, an observance lasting eight days.

The Week of Prayer for Christian Unity is annually coordinated by the World Council of Churches, with participation by its member Churches, which include the Assyrian Church of the East, the Oriental Orthodox Churches, the Eastern Orthodox Churches, the Old Catholic Church, the Moravian Church, the Lutheran Churches, the Anglican Communion, the Mennonite Churches, the Methodist Churches and the Reformed Churches, as well as the Baptist Churches and the Pentecostal Churches. The Roman Catholic Church, which is an observer in the World Council of Churches, also celebrates the Week of Prayer for Christian Unity.