Australian Cardinal George Pell is the most senior Catholic ever convicted of such crimes.
The former Vatican treasurer is the most senior Catholic figure ever to be found guilty of sexual offences against children.
Pell abused the 13-year-old choir boys in a Melbourne cathedral in 1996, a jury ruled last year.
The cardinal, 77, maintains his innocence and has lodged an appeal.
In sentencing Pell on Wednesday, a judge said the cleric had committed "a brazen and forcible sexual attack on the two victims".