Ahmed Maher, Mohamed Adel and Ahmed Douma each received three-year prison sentences and fines of 50,000 Egyptian pounds ($7,236) for crimes committed during a November demonstration outside a Cairo court where Maher was surrendering for questioning over allegations he organized a prior illegal protest, Ahram Online said.
The three activists were at the forefront of the 2011 uprising that toppled Hosni Mubarak's government and can appeal the ruling.
The convicted men were protesting a new law requiring prior authorization from Egypt's Interior Ministry before holding demonstrations. Their arrests worried human rights groups that Egypt's new political establishment was returning to the police state of the Mubarak era, al-Masry al-Youm said.
A similarly harsh sentence against 14 women supporting former President Mohamed Morsi last month was reduced to a one-year suspended sentence for each, allowing them to leave prison, Ahram Online noted.