Major religious affiliations in Australia by census year
Since the 1980s, Catholicism has been largest Christian denomination in Australia constituting around one quarter of the overall population becoming slightly larger than the Anglican and Uniting churches combined. Up until the 2016 census, adherents had been recorded as growing both numerically and as a percentage of the population, however the 2016 census found a fall in both overall numbers, and the percentage of Catholics as a proportion of Australia: with 5,291,839 Australian Catholics (around 22.6% of the population) in 2016 down from 5,439,257 in the 2011 census (25.3% of the population).
Until the 1986 census, Australia's most populous Christian church was the Anglican Church of Australia. Since then Catholics have outnumbered Anglicans by an increasing margin. The change is partly explained by changes in immigration patterns. Before the Second World War, the majority of immigrants to Australia came from the United Kingdom and most Catholic immigrants came from Ireland. After the war, Australia's immigration diversified and more than 6.5 million migrants arrived in the following 60 years, including more than a million Catholics from Italy, Malta, Lebanon, the Netherlands, Germany, Poland, Croatia and Hungary.
At the 2016 Census, the ancestries that Australian Catholics most identified with were 'English' (1.49 million), 'Australian' (1.12 million), Irish (577,000), Italian (567,000) and Filipino (181,000).
Despite a growing population of Catholic, weekly Mass attendance has declined from an estimated 74% in the mid-50's to around 14% in 2006.
There are seven archdioceses and 32 dioceses, with an estimated 3,000 priests and 9,000 men and women in institutes of consecrated life and societies of apostolic life, including six dioceses which cover the whole country: one each for those who belong to the Chaldean, Maronite, Melkite, Syro-Malabar and Ukrainian rites and one for those serving in the Australian Defence Forces. There is also a personal ordinariate for
former Anglicans which has a similar status to a diocese.