The Congregational Union of Australia was a congregational denomination in Australia.

Two hundred and sixty of its congregations joined the Uniting Church in Australia, which was formed in 1977 by the union of congregations of the Congregational Union, Methodist Church of Australasia, and Presbyterian Church of Australia.

The remaining fourty congregations and formed the Fellowship of Congregational Churches. Some of the ecumenically aligned congregations left that demonination in 1995 to form the Congregational Federation of Australia.