Most were arrested 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.
Political turmoil has deepened in Egypt since the army overthrew President Mohamed Mursi of the Muslim Brotherhood last July. Security forces have killed hundreds of Brotherhood members in the street, and arrested thousands of others.
"The court has decided to sentence to death 529 defendants, and 16 were acquitted," lawyer Ahmed al-Sharif told Reuters. The ruling can be appealed.
The charges against the group, on trial in Minya since Saturday, include violence, inciting murder, storming a police station, attacking persons and damaging public and private property.
Only 123 of the defendants were present. The rest were either released, out on bail or on the run.
"This is the quickest case and the number sentenced to death is the largest in the history of the judiciary," said lawyer Nabil Abdel Salam, who defends some Brotherhood leaders including Mursi.
State television reported the sentences without comment. A government spokesman did not immediately respond to calls.
"When the trial starts on Saturday and it is just a procedural hearing, and the judge doesn't listen to any lawyers or witnesses and doesn't even call the defendants, you are before a group of thugs and not the judiciary," Walid, a relative of one of the defendants, said by phone.
It was not possible to confirm his account of the proceedings independently.
The government has declared the Brotherhood a "terrorist" group. The Brotherhood says it is a peaceful movement.