The Catholic Church in Australia is part of the worldwide Catholic Church under the spiritual and administrative leadership of the Holy See. The religion arrived in Australia with the First Fleet in 1788, and since the 1960s, has remained stable at around one quarter of the Australian population. In 2016, there were 5,439,268 Australian Catholics, representing 23% of the overall population, and the Church was the single largest non-government provider of education, health, community and aged care services. Australia has 32 dioceses and 1,363 parishes. It has more than 180 congregations of sisters, brothers and religious priests, working in diverse vocations ranging from education, to health care, poverty alleviation, social justice, and cloistered contemplation. The Australian Catholic Bishops Conference, the national episcopal conference of the Catholic bishops of Australia, is headed by the Archbishop of Melbourne, Denis Hart, and there is one living Australian cardinal: the current Prefect of the Secretariat for the Economy, George Pell. One Australian has been recognised as a saint by the Catholic Church: Mary MacKillop, who co-founded the Josephite religious institute of sisters in the 19th century.
Catholicism arrived in Australia with the establishment of a British colony at New South Wales and the first Australian Catholics were mainly of Irish origin. British authorities initially suppressed the religion, but priests were permitted to stay from the 1820s and the colony gained its first Catholic Church in 1836. The first nuns arrived in 1838 founding a strong tradition of women religious working in health, education and prison chaplaincy. Australia gained diocesan status in 1846, and the Church flourished through the 19th century with the establishment of dioceses, parishes hospitals and schools across the continent. The diversity of Australian Catholics increased greatly with 20th century post war immigration, with large numbers coming from Italy, the Mediterranean, Asia and later Africa. Catholics have been prominent in Australian political and cultural life, and religious in public life today straddle the political divides - from advocating on "social conservative" causes such as opposition to abortion, euthanasia and marriage redefinition, to working in "social justice" causes such as advocacy for refugees, indigenous people, and workers.