The Catholic Church in Victoria has confirmed 620 cases of child sexual abuse by clergy since the 1930s.

It is the first time the church has publicly released the figure.

In a submission to a Victorian Parliamentary inquiry, the church revealed the cases of criminal child abuse have been upheld by its own complaint procedure.

It says the cases go back 80 years, but the vast majority relate to abuse in the 1960s, '70s and '80s.

Most of the cases reported came from Ballarat and Mortlake, in regional Victoria, and Oakleigh and Rupertswood.

The church says it is still assessing 45 cases.

It says of all the claims upheld, only 13 cases relate to abuse committed after 1990.

The total figure does not include cases in which the victim approached the police and not the church.

The Catholic Archbishop of Melbourne, Denis Hart, says the church will cooperate fully with the inquiry.

"In [the submission] Facing the Truth, we have been open about the horrific abuse that has occurred in Victoria and elsewhere," he said.

"It is shocking and shameful that this abuse, with its dramatic impact on those who were abused and their families, was committed by Catholic priests, religious and church workers.

"This submission shows how the church of today is committed to facing up to the truth and to not disguising, diminishing or avoiding the actions of those who have betrayed a sacred trust."