Called by some the "liquid continent" the Pacific is by far the largest region of the WCC geographically. It covers the South Pacific ocean from Papua New Guinea on the eastern side to Tahiti on the west and from the Marshall Islands in the north to New Caledonia in the south. It was the last of the regions to be fully acknowledged in the WCC structure and its mechanisms of representation on the governing bodies and committees. The history of all the Pacific churches involved in the ecumenical movement goes back to the period of the missionary movement from the 18th to the 20th century in which Pacific islanders themselves took an active part, preaching the Gospel from one island to the other. None of these churches was at the founding assembly of the WCC. Yet in 1961 already the Anglican and Protestant churches of the region which had obtained their autonomy from the mission societies decided to create their regional ecumenical organization, the Pacific Conference of Churches, founded in 1966. At the Fifth Assembly of the WCC  in 1983 in Vancouver, on the Pacific rim, the region and its issues, in particular nuclear testing came firmly on the agenda of the ecumenical movement and the WCC through a plenary presentation of the PCC and the Pacific churches.

Most of the island nations have a national council of churches or similar body and in all of these the local Catholic Church is a full member. At the regional level the Catholic Episcopal Conference of the Pacific and the Catholic Bishops' Conferences of Papua New Guinea and the Solomon Islands are members of the PCC. The Pacific has three sub-regions, Melanesia, Polynesia and Micronesia but the churches have not organized themselves sub-regionally. The churches in Australia and Aotearoa New Zealand have strong relationships with the Pacific churches through mission and cooperation but are not part of the region and not members of the PCC (see also Asia). The WCC has 17 member churches in the Pacific with a total membership of 2,5 million Christians. Since about two decades Pentecostalism and other new religious movements have made inroads in the region and changed considerably the face of Christianity. In the early 1990s a study was initiated by the WCC Pacific Regional Group and conducted under the auspices of the PCC which resulted in the publication Winds of Change - Rapidly Growing Religious Groups in the Pacific Islands (1994). It was completed by another major study Globalization and the Reshaping of Christianity in the Pacific Islands (2007) under the responsibility of the Pacific Theological College.

The main church bodies at the regional level are:

• Pacific Conference of Churches (PCC)
• Catholic Epsicopal Conference of the Pacific (CECP)
• Evangelical Fellowship of the South Pacific (EFSP)