A military court in Upper Egypt's Assiut sentenced on Sunday 175 people to life in prison and acquitted 10 on charges of committing violence and storming the Malawy museum in Minya in 2013.
A further 42 defendants received varying prison sentences.
The defendants are supporters of ousted president Mohamed Morsi, arrested during unrest that followed the dispersal in 2013 of sit-ins demanding his reinstatement.
Hundreds of those arrested in 2013 were later referred by prosecution to military courts.
Egypt's 2014 constitution gives military tribunals jurisdiction over crimes committed against army facilities and personnel. The article has prompted controversy, with opponents insisting that civilians should not be subject to military trials.
Last May, six people were executed after being convicted by a military court.