In Australia, Presbyterianism is the fourth largest denomination of Christianity, with nearly 600,000 Australians claiming to be Presbyterian in the 2006 Commonwealth Census. Presbyterian churches were founded in each colony, some with links to the Church of Scotland and others to the Free Church. There were also congregations originating from United Presbyterian Church of Scotland as well as a number founded by John Dunmore Lang. Most of these bodies merged between 1859 and 1870, and in 1901 formed a federal union called the Presbyterian Church of Australia but retaining their state assemblies. The Presbyterian Church of Eastern Australia representing the Free Church of Scotland tradition, and congregations in Victoria of the Reformed Presbyterian Church, originally from Ireland, are the other existing denominations dating from colonial times.

How many members make up the Presbyterian church in Australia?