cooperative international organization of Presbyterian, Congregational, and Reformed churches that was formed in Nairobi, Kenya, in 1970 by the merger of the International Congregational Council with the Alliance of the Reformed Churches Throughout the World Holding the Presbyterian System (also called the World Alliance of Reformed Churches).

The International Congregational Council, organized in London in 1891, was an association of Congregational and some Independent and United churches. Its purpose was to foster fellowship and service among its members, but it had no authority over them.

The Alliance of the Reformed Churches Throughout the World Holding the Presbyterian System was organized in London in 1875 by Presbyterian and Reformed churches. It was the oldest international Protestant confessional body in the world. A voluntary organization, the Alliance encouraged fellowship and cooperation among its member churches and promoted their common interests. The World Alliance of Reformed Churches had approximately 70 million members in the late 20th century.