It paves the way for compensation to be paid to people who were sexually abused as children by church figures and puts pressure on other institutions to follow suit.
The country's Catholic bishops and leaders of its religious orders committed to signing on to the 3.8 billion Australian dollar (£2.2 billion) national plan on Wednesday.
The church is the first non-government institution to opt into the plan and estimates it will itself be liable for about one billion dollars (£568 million) in compensation.
Federal Social Services Minister Dan Tehan expects more institutions to follow, saying there could be further announcements as early as Thursday.
Archbishop of Adelaide Philip Wilson last week became the most senior Catholic cleric in the world to be convicted of covering up child sex abuse. He faces a potential two-year prison term when he appears in court in June to be sentenced for protecting a paedophile priest in the 1970s.
Pope Francis' former finance minister Cardinal George Pell faces trial on sexual assault charges in Australia.
The exact details and nature of the charges have not been disclosed to the public, but police have described them as "historical" sexual assaults, meaning they are alleged to have occurred decades ago.
Catholic leaders have long backed a national redress plan but the churches, charities and other non-government institutions needed the state and territory governments to sign on first.
Western Australia is the final state to join, although state Attorney-General John Quigley said the negotiations with the federal government could be finalised within two months.
The Australian Catholic Bishops Conference and Catholic Religious Australia on Wednesday confirmed the church will enter the plan when it becomes law.
Mr Tehan said the plan was on track to begin on 1st July if legislation passed the Senate.
Sydney Archbishop Anthony Fisher said the church expected to be paying out to survivors for "many years to come".
The plan will cover about 60,000 people who were sexually abused as children by institutional figures. Payments will be capped at 150,000 dollars (£85,000), with previously received compensation being deducted from any new amount.
The plan was recommended by the Royal Commission into Institutional Responses to Child Sexual Abuse, which made its final report in December.
Australia's longest-running royal commission - which is the country's highest form of inquiry - had been investigating since 2012 how the Catholic Church and other institutions responded to sexual abuse of children in Australia over 90 years.
The inquiry heard the testimonies of more than 8,000 survivors of child sex abuse. Of those who were abused in religious institution, 62 per cent were Catholics.
Reporting by Associated Press. Received via Press Association.
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