Father Peter Carr, 73, was exposed when the two women now in their 40s - one a solicitor, the other a singer - swapped online recollections about how he rubbed paint on their naked bodies before school plays.
They complained to police who found that other girls invited to join productions at the boys' school in the Forest of Dean, Gloucestershire, were subjected to similar abuse.
Gloucester crown court judge Martin Picton told Carr that he had done the church "much damage".
"What you did was not minor. They [the girls] have had to face life with a sense of being degraded and humiliated," he said.
"The shows should have been the high points of their childhoods but the pleasure is forever tainted by the abuse they suffered at your hands."
Carr put on two plays - Sinbad the Sailor and Tom Thumb - that he said required the application of make-up to the girls' bodies.
During rehearsals he smeared paint over the naked girls, sometimes when they were alone when him. He has claimed that he "only wanted to put on good show".
One of the first two victims, now a 49-year-old singer and osteopath, said she had never previously told of the abuse but Carr had become a "monster in her mind".
The prosecutor, Ian Dixey, told the court three other women had come forward making identical complaints since reports of the case appeared last week.
Noel Lucas, defending, said his client's life was in ruins and the church would carry out an internal inquiry leading to further humiliation.
Carr was a member of the Salesian order, founded by Don Bosco in the 19th century to help poor young boys. The order condemned the abuse and apologised to the victims.
The woman who went on to become a singer said after the sentencing that she had not expected Carr to be jailed.
"I didn't think a prison sentence would necessarily change anything because he doesn't think he has done anything wrong," she said. "He doesn't even have an inkling of how he has affected our lives.
"I feel quite sorry for him now. If you had asked me in my 20s, I might have wanted revenge, but now I am just satisfied that he isn't going to die with everyone saying what a fantastic priest he is."
Carr, whose duties included teaching drama, was convicted last December of eight counts of indecently assaulting six different girls. He pleaded guilty last week to a seventh count after another woman came forward. The offences were committed between 1969 and 1975.Carr, now of Battersea, south London, is under a sexual offences prevention order (Sopo) banning him from working or living with children.
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