Riot police used water cannons on anti-government protesters outside Georgia's parliament building in the capital, Tbilisi.
Thousands of people demonstrated on Monday evening calling for reform to the country's electoral system.
Several activists and a politician were arrested early on Tuesday, opposition leader Giorgi Vashadze said.
Rallies have been held for the last two weeks, with activists demanding proportional representation.
Georgia was due to switch to the proportional representation electoral system in 2024, but the opposition is calling for the date to be brought forward.