Egypt has delivered verdicts for more than 700 people over a pro-Muslim Brotherhood sit-in after President Mohammed Morsi was ousted in 2013.
Rights group Amnesty International has called the trial "grossly unfair" and a violation of Egypt's constitution.
Violence erupted at the 2013 protest in Cairo's Rabaa al-Adawiya square, with hundreds killed by security forces.
Earlier this year, Egypt's parliament gave military officers immunity for the deadly crackdown and any crimes committed between July 2013 and January 2016.
Those who were sentenced in the mass trial were accused of security-related offences including incitement to violence, murder and organising illegal protests.