The sentences were handed down on six men and a woman by a court in the Mediterranean port city of Alexandria, the state news agency MENA reported.
Each was also fined around USD 7,200.
The seven, who include prominent activists Hassan Mostafa and Mahienour al-Massry, were found guilty of "attacking security forces, rioting and cutting off roads" during a December 2 protest.
That protest was organised without prior permission as required under the new law, MENA said, adding that the two are on the run along with another activist.
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In November, the authorities passed a new law that bans all demonstrations except those sanctioned by the police.
The law is firmly opposed by rights groups and secular activists.
On December 22, a Cairo court sentenced three activists, Ahmed Maher, Ahmed Douma and Mohamed Adel, who spearheaded the anti-Mubarak revolt, to three years in jail for organising an unauthorised protest.
It was the first such verdict against non-Islamist protesters since the army overthrew president Mohamed Morsi in July, and was seen by rights groups as part of a widening crackdown on demonstrations by the military-installed authorities.
The military justified its overthrow of Morsi - Egypt's first feely elected president - as a response to massive protests against his turbulent year-long rule.