Cardinal Pell had been found guilty of sexually penetrating a child under the age of 16 as well as four charges of an indecent act with a minor.
Judge Peter Kidd told the courts that the 77-year-old was "brazen".
He said, "you were confident your victims would not complain."
"The offending which the jury has found you have engaged in was, on any view, breathtakingly arrogant," the judge told Pell - saying he had committed a "grave abuse of his power."
The criminal offences involving two choirboys - who the judge referred to as 'R' and 'J' - occurred between December 1996 and early 1997 at St Patrick's Cathedral, months after Pell was inaugurated as archbishop of Melbourne's Catholic church.