The 81-year-old former archbishop of Melbourne and Sydney died from heart complications on Tuesday following hip surgery.
Cardinal Pell was the Vatican's top finance minister before leaving Rome in 2017 to stand trial in Melbourne for child sexual abuse offences.
The following year, he was convicted of molesting two teenage choirboys in the sacristy of Melbourne's St Patrick's Cathedral while archbishop in 1996.
However he maintained his innocence and in 2020 his convictions were quashed by the High Court.
Archbishop of Melbourne Peter Comensoli, who knew Cardinal Pell for more than a decade, called him a mentor, father figure and friend.
"The cardinal has been one of the great churchmen of Australia and internationally," the archbishop told reporters on Wednesday.
"He, over many years, has been a forthright defender of the faith, a great gospel man."
Cardinal Pell was born in Ballarat on June 8, 1941, the eldest child of George, a boxing champion, publican and non-practising Anglican, and Margaret, a devout Catholic.
He was ordained a priest at St Peter's Basilica in 1966 and returned to his home town in 1973 to work as a director of the city's Aquinas campus.
He succeeded Sir Frank Little as Melbourne archbishop in 1996 and moved to Sydney to be archbishop there five years later.
At that time, a man claimed Cardinal Pell sexually abused him in 1962 when he was an altar boy. He denied the allegation and in 2003 became a cardinal in the Vatican.
In 2013, Cardinal Pell appeared before a Victorian parliamentary inquiry into child abuse, acknowledging that the church had covered up the "foul crime" and sometimes placed priests above the law.
The following year Pope Francis appointed him cardinal prefect of the Secretariat for the Economy, which made him the Vatican's third most powerful man.
After his convictions were quashed in 2020, Francis tweeted, "we've been witnessing the persecution that Jesus underwent and how He was judged ferociously, even though He was innocent."
Speaking from Rockhampton on Wednesday, Prime Minister Anthony Albanese expressed his condolences.
A service for Cardinal Pell will be held at the Vatican in the coming days with a funeral mass to follow at St Mary's Cathedral in Sydney. His body will be returned to Australia and buried in St Mary's crypt.
Archbishop Anthony Fisher, now considered Australia's most senior Catholic, said the death came as a shock.
"Please pray for the repose of the soul of Cardinal Pell, for comfort and consolation for his family and for all of those who loved him and are grieving him at this time," he wrote on Facebook.
The bells at St Mary's Cathedral, the home of Sydney's Catholic Archdiocese, tolled 81 times on Wednesday morning.
The president of the Australian Catholic Bishops Conference, Archbishop Timothy Costelloe, said the cardinal was a man of deep and abiding faith.
Victorian government minister Steve Dimopoulos noted it would be a difficult day for survivors and victims of abuse and their families.
Shine Lawyers, who represent the father of one Cardinal Pell's accusers, said the legal claim against the church and the cardinal's estate would continue.
The father is seeking damages, claiming he suffered nervous shock after being informed of allegations. His son died of a drug overdose in 2014.
Melbourne solicitor Viv Waller, who represented Cardinal Pell's surviving accuser, said he would be remembered as "not adopting a very compassionate response to (abuse revelations) but instead being offensive about it and protecting the church".
Cardinal Pell's legacy would be mixed because of the alleged abuse and cover-ups, Australian Catholic University's Miles Pattenden said.
"But Cardinal Pell was the most powerful Australian ever to have risen through the ranks of the Roman Catholic Church," he told AAP.
"He put Australia on the map in the Vatican."
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