Known as the "Butcher of Bosnia", Mladic led forces during the massacre of Bosnian Muslims (Bosniaks) in Srebrenica and the siege of Sarajevo.
The UN tribunal in The Hague convicted him on 10 of the 11 charges.
Mladic, 74, was not in court when the sentence was read out. He had been removed for shouting at the judges.
"It's a lie. Everything you said in this courtroom is a lie," he said.
The outburst came after the judges rejected a request by his team to halt the proceedings because of Mladic's high blood pressure.
