"No religion" is now the most common answer Australians give: 38.9% at the 2021 census, ahead of Catholics at 20% and Anglicans at 9.8%. Christianity overall fell below half the population for the first time, to 43.9%. Australia has secularised faster than almost any comparable country, and because the census has asked the question since 1911, the shift can be traced year by year rather than estimated.
The Question You Do Not Have to Answer
Question 19 on the Australian census asks "What is the person's religion?" and is the only optional question on the form — a compromise written into the Census and Statistics Act when the census began, at a time when religious identity was politically sensitive between Irish Catholics and the Protestant establishment.
Roughly 7% of people leave it blank, which means the published percentages are calculated against a slightly incomplete base. The Australian Bureau of Statistics reports both, and analysts generally use the figures including non-response.
The optional status also produced Australia's most famous census campaign. In 2001 an email chain urged people to write "Jedi" on the grounds that 10,000 responses would force official recognition — which was never true. More than 70,000 did it anyway, and the ABS classified them as "not defined". The number has fallen at every census since, to around 12,000 by 2021.
How Fast It Happened
In 1966, 0.8% of Australians reported no religion. In 1971, after the instruction on the form was changed to include "if no religion, write none", the figure jumped to 6.7%. It reached 12.9% in 1991, 22.3% in 2011, 30.1% in 2016 and 38.9% in 2021.
Anglicanism has borne the heaviest losses. It was the largest single denomination in Australia for most of the twentieth century, at around 40% in the 1930s; it is now under 10% and its median member age is in the late fifties.
Catholicism has held up better, largely because of immigration — Italian and Maltese arrivals after the war, then Filipino, Vietnamese, Lebanese, Indian and more recently South American communities. It overtook Anglicanism as the largest denomination in 1986 and remains so.
Section 116 and What It Does Not Do
Australia has no established church. Section 116 of the Constitution bars the Commonwealth from making any law establishing a religion, imposing religious observance, prohibiting free exercise, or requiring a religious test for public office.
Its reach is narrower than the American First Amendment in two ways. It binds only the Commonwealth, not the states, and the High Court has read it restrictively — most importantly in the 1981 DOGS case, which upheld federal funding of religious schools on the grounds that funding is not establishment.
That ruling shapes Australian education profoundly. About a third of Australian school students attend non-government schools, the overwhelming majority of them religious, and they receive substantial Commonwealth funding. Australia's church-state separation is real in law and quite porous in money.
Sixty Thousand Years of Aboriginal Spirituality
The oldest continuing religious traditions on the continent are also the ones the census captures least well. Aboriginal and Torres Strait Islander traditional beliefs were recorded by only around 8,000 people in 2021, a figure that badly understates practice, because a majority of Indigenous Australians who answered reported a Christian affiliation and many hold both.
The English term "the Dreaming", a nineteenth-century translation of words such as the Arrernte Altyerre, describes something without a good English equivalent: the creative era in which ancestral beings formed the land, and a present-tense reality embedded in specific places, songs and obligations. Each language group has its own, and there are hundreds.
Because the beliefs attach to particular sites, they intersect directly with land law. Uluru was returned to Anangu ownership in 1985 and climbing it was prohibited from October 2019 at the traditional owners' request. The destruction of the 46,000-year-old Juukan Gorge rock shelters in 2020 under a valid mining approval triggered a parliamentary inquiry and the resignation of Rio Tinto's chief executive.
The Missions, and Why the Legacy Is Contested
Christian missions were central to how the colonial state managed Aboriginal people. Missions and government reserves housed a large share of the Indigenous population into the twentieth century, and church-run institutions took in many of the children removed under the policies documented in the 1997 Bringing Them Home report.
The churches have since apologised — the Uniting Church, the Anglicans and the Catholic bishops all issued statements through the 1990s — and the national apology followed in Parliament in February 2008.
The legacy is genuinely mixed rather than simply negative, and Indigenous Australians say so in both directions. Missionaries recorded languages that would otherwise be lost and some mission communities became bases for land rights claims; the same institutions enforced removals and suppressed ceremony. Both are part of why Indigenous Australians today report Christian affiliation at rates close to the national average.
Islam, Hinduism and the Migration Effect
Non-Christian religions have grown quickly from small bases, and almost entirely through migration. Islam reached 3.2% in 2021, Hinduism 2.7%, Buddhism 2.4% and Sikhism 0.8% — Sikhism the fastest-growing religion in Australia in percentage terms, roughly doubling between censuses.
Hinduism's growth tracks Indian migration, which has made India the largest source of permanent migrants to Australia in recent years. Buddhism arrived earlier, with Vietnamese refugees after 1975 and Chinese migration from the 1980s, and is the one non-Christian religion whose share has begun to plateau.
Australia's Muslim history is older than most Australians realise. Macassan trepang fishers from Sulawesi visited northern Australia for perhaps two centuries before 1906, leaving loanwords in Yolŋu languages, and the "Afghan" cameleers of the 1860s onwards built the country's first mosque at Marree in South Australia around 1861.
Chaplains in State Schools
Australia's most litigated church-state question is the National School Chaplaincy Program, launched in 2007, which funds chaplains in thousands of state primary and secondary schools. A Toowoomba father, Ron Williams, took it to the High Court twice.
He won both times, in 2012 and 2014, but not on religious grounds. The Court struck the funding down as beyond the Commonwealth's spending power, leaving section 116 largely untouched, and the program was simply restructured as grants to the states and continued.
Rules on who may be hired changed in 2022, when the Commonwealth required states to allow secular student welfare officers as an alternative. Several states now do. The episode is a fair summary of Australian practice: the constitutional protection is thin, and the arguments get resolved on federalism instead.
Where the Non-Religious Actually Are
"No religion" is not evenly spread. It runs highest in inner-city Melbourne, Canberra, Hobart and coastal Tasmania and parts of northern New South Wales, in some statistical areas exceeding 55%. It runs lowest in western Sydney, where several suburbs report Christian or Muslim affiliation above 80%.
The pattern is a migration pattern more than a belief pattern. Australia's most religious places are its most recently settled migrant suburbs, and its least religious are its most Anglo, most educated and most established ones — the reverse of the assumption that diversity and secularity travel together.
The census also shows that only around 2.4% of Australians actively describe themselves as atheist when offered the write-in option. The vast majority of the 38.9% simply have no religion rather than a position about religion, which is a different thing and behaves differently in surveys.
The 2017 same-sex marriage postal survey doubled as the largest survey of Australian moral attitudes ever conducted: 79.5% of eligible voters responded and 61.6% voted yes. Parliament legislated in December of that year.
The geography of the no vote is instructive, because it did not follow the map of church attendance. The strongest no results came from a cluster of seats in western Sydney with large migrant Muslim and Christian populations, while nominally Catholic and Anglican heartlands voted yes comfortably.
That pattern captures the Australian situation better than the census totals do. Institutional Christianity retains organisational weight — in schools, hospitals, aged care and chaplaincy programs — while its capacity to move votes has largely gone, concentrated now in specific migrant and evangelical communities rather than in the historic denominations.
Where This Leaves the Churches
The Royal Commission into Institutional Responses to Child Sexual Abuse, which reported in December 2017 after five years, found that 61.8% of survivors who spoke about abuse in religious institutions had experienced it in Catholic ones, and identified 1,880 alleged perpetrators across Catholic institutions alone. It accelerated a decline already underway.
What survives is a large religious infrastructure attached to a shrinking religious population: church-affiliated schools educating hundreds of thousands, Catholic hospitals as the largest non-government provider, and denominational aged care across the country, all increasingly staffed and used by people who tick "no religion".
Australia is not unusual in secularising. It is unusual in how completely it has done so within two generations, and in having a census that recorded every step — a sharper record than exists for most of the countries of Oceania around it, where church membership remains far higher. Canada, the closest comparison in size and settler history, has followed almost the same curve a few years behind.
