Gerald Francis Ridsdale, 79, was given an eight-year sentence after pleading guilty to 30 new charges against 14 boys and girls between 1961 and 1980, conduct described by the judge as "evil hypocrisy."

But the notorious pedophile, already serving time for a campaign of abuse dating back to 1961 when he was ordained, will not be eligible for parole until April 2019.

The protection of the Catholic church, which moved him from parish to parish throughout his career, meant his offending spanned three decades.

He abused 53 children in that time.

They included children of parishioners, wards of the state, altar servers, twin brothers and a girl as young as four-years-old.

It wasn't until 1993 that he was de-frocked.

Two years later, he was jailed for 18 years.

Clergy abuse victims advocate Chris Wilding said Ridsdale was the "pin-up boy for pedophiles within the Roman Catholic Church".

"He is the most prolific in this point at time," Ms Wilding said.

Ridsdale portrayed himself as the "friendly priest", luring his victims with inducements such as lollies and money to gain their trust.

He befriended victims and set up an after-school boys gathering, which was the setting for crimes against five children.

Many of Ridsdale's victims were extremely vulnerable - some being wards of the state or from broken homes.

Victorian County Court Chief Judge Michael Rozenes said he was supposed to avoid a crushing sentence that would prevent the former Catholic priest living a useful life after his release, but in some cases a criminal's age meant the just sentence was crushing.

The offending was a blatant breach of trust, Judge Rozenes said, adding that Ridsdale used his position within the Church to commit various serious sexual acts upon his victims.

"There is no doubt your conduct plummets to the depths of evil hypocrisy," Judge Rozenes said.

"Your conduct has given rise to disastrous, catastrophic and at times tragic results."

Ridsdale told one victim, an altar boy, that the abuse was a secret between them, and merely a "game" they played.

One girl was abused in a church confessional box after Ridsdale told her she was wicked and needed to be punished.

She was forced to say "forgive me Father for I have sinned", words usually uttered in a confession, before he abused her.

Ridsdale showed no expression when he was sentenced and slowly left the dock, using a walking frame.