Eighty-four-year-old Leslie Sheahan, a Ballarat North priest in the 1960s, was on Thursday given a 12-month sentence by magistrate Michelle Hodgson - three of which were to be served immediately.

Ms Hodgson said the historical sex offence was indicative of the culture of silence and accountability by members of the clergy who have abused positions of trust.

"Slowly but surely we have come to recognise people in positions of power are taking advantage of people," she said.

Sheahan pleaded guilty to unlawful/indecent assault of a girl - a historical charge which predates  the sexual  penetration of a child charge introduced in 1980s - in February.

A victim impact statement read in court detailed how the victim's attempts to report the incident were dismissed by the Catholic Church, with one priest accusing her of lying and being a naughty girl.

The victim's statement suggested the Catholic Church of Australia's Towards Healing investigation concluded the allegations would not stand up in a civil court case, which caused the victim crippling self-doubt.

"The long lasting and deep betrayal by the Catholic Church has robbed me of my belief system," the statement read.

"I know I will never be buried by a Catholic priest."

The statement went onto read the victim and her family had suffered enormous psychological damage as a result of the incident. 

The court head Sheahan offered a "bizarre" explanation for the crime, which occurred at Horsham between 1970-1971, telling police he thought he was playing a "practical joke" on the young girl's mother.

In placing Sheahan on the sex offenders register for eight years, Ms Hodgson said she did not accept the former priest's explanation.

Ms Hodgson said she understood a period of imprisonment would be onerous on the frail Sheahan, who appeared in court with a walking aid.

However, the principles of denunciation, general deterrence and just punishment formed part of her sentencing considerations she said.

"The community should know the courts denounce such behaviour," she said.

Sheahan was granted appeal bail and will appear at a County Court sitting in Ballarat at a date to be fixed.