The ruling was the biggest mass death sentence handed out in Egypt's modern history, lawyers said.
Turmoil has deepened since the army overthrew Egypt's first freely elected president, Mohamed Mursi of the Muslim Brotherhood, in July.
streets, and arrested thousands.
Most of the defendants at Monday's hearing were detained during clashes which erupted in the southern province of Minya after the forced dispersal of two Muslim Brotherhood protest camps in Cairo on August 14.
Islamists have also stepped up attacks on the police and army since Mursi's ouster, killing hundreds and carrying out high profile operations against Interior Ministry officials.
"The court has decided to sentence to death 529 defendants, and 16 were acquitted," lawyer Ahmed al-Sharif told Reuters.