Presiding judge Bertram Schmitt sentenced Ongwen to a total period of 25 years in prison.
Ongwen and his men were responsible for attacks on refugee camps in northern Uganda.
The International Criminal Court on Thursday sentenced Dominic Ongwen, a Ugandan child soldier who became a commander in the notorious Lord's Resistance Army (LRA), to 25 years in jail for war crimes and crimes against humanity.
Ongwen, 45 - whose nom de guerre was "White Ant" - was found guilty in February of 61 charges, including murders, rapes and sexual enslavement during a reign of terror in the early 2000s by the LRA, led by the fugitive Joseph Kony.