Judge Peter Kidd has jailed Pell for six years years with a minimum three years and eight months to serve.

Earlier: Disgraced cardinal George Pell has been told to expect "significant" prison time when he's sentenced in Melbourne's County Court today for sexually abusing two teenage boys in 1996.

Chief Judge Peter Kidd will hand down his sentence on Wednesday, three months after Pell was found guilty of orally raping a 13-year-old choirboy and molesting another at St Patrick's Cathedral after a Sunday mass.

Pell, who was until late-February the Vatican's treasurer, is the highest- ranking Catholic to be convicted of child sexual abuse.

Anticipating huge public interest in the sentence, the judge will permit a camera in court to broadcast his remarks live globally.

The courtroom is also expected to be packed with abuse survivors who have their own interest in the result, beyond that of Pell's surviving victim, now aged in his 30s.

He was orally raped by Pell in the priest's sacristy after a Sunday mass in December 1996, forced to watch as Pell molested his 13-year-old friend, and then molested again by Pell a month later.

The other boy died in 2014.

Cathy Kezelman from the trauma recovery-focused Blue Knot Foundation says the sentence represents the personal struggle for justice of many other abuse survivors and the outcome is likely to be emotional and polarising.

For some, any sentence won't be enough while others, still reeling from the verdict, will likely be outraged, she says.

"For too long, hermetically sealed systems of power, such as within the Catholic Church, have called the shots, protecting the church, its hierarchy and themselves," Dr Kezelman said.

"Hopefully this sentence can herald fundamental change to the Church and other institutions, starting with accountable, responsible and transparent leadership, hierarchy and culture."

Pell, 77, was convicted in December of one charge of sexually penetrating a child and four of committing indecent acts with a child. Each offence carries a 10-year maximum prison sentence.

Senior crown prosecutor Mark Gibson, SC, foreshadowed in a pre-sentence hearing that Pell would spend "significant time" in prison, including likely long periods in lockdown because of his high profile.

Pell maintains his innocence and intends to challenge the conviction in the Court of Appeal, which will be heard in June.

He has already served two weeks behind bars.

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