Ntaganda faced the possibility of life imprisonment after he was found guilty on 18 counts of war crimes and crimes against humanity in July.
Nicknamed the “Terminator,” Ntaganda oversaw widespread attacks on civilians and recruited child soldiers.
The court considered it to be proven that such crimes occurred while Ntaganda headed the Patriotic Forces for the Liberation of Congo (FPLC) – the military wing of the Union of Congolese Patriots political group – in north-eastern Ituri province, between 2002 and 2003.
He was also responsible for the sexual slavery of children, said Robert Fremr, the presiding judge from Czech Republic.
The court found him guilty of other charges as well, including murder and rape.
Ntaganda surrendered to the U.S. embassy in the Rwandan capital Kigali in 2013, after eluding capture for seven years.
He maintained his innocence during the trial, saying that he was a revolutionary, not a criminal during his final statement.