An estimated 30,000 opposition supporters have rallied in the Georgian capital against the government's Russia policy and the Kremlin's backing of separatists in the breakaway Abkhazia and South Ossetia regions.
Carrying Georgian and Ukrainian flags and placards that read "Stop Putin!," the protesters gathered on Tbilisi's main thoroughfare, following the call of the former President Mikheil Saakashvili's United National Movement party (UNM).
Saakashvili addressed the rally by video link from Kyiv as the cheering crowd chanted his name.
The former president said, "Let's show Georgia's government that the nation is united against the serious threat to its independence, its future."
Saakashvili's UNM party has accused the ruling Georgian Dream coalition government of not confronting what it claims is Russia's creeping annexation of Abkhazia and South Ossetia.
Georgian Dream, formed by former Prime Minister and billionaire tycoon Bidzina Ivanishvili, came to power in 2012 and ended a decade-long rule of staunchly pro-Western Saakashvili and his UNM party.
Many former top Saakashvili officials have been arrested over the last two years for alleged wrongdoing, prompting warnings from the West over selective justice and persecution of political opponents.
Moscow-backed Abkhazia and South Ossetia broke away from Georgia after conflicts in the 1990s following the break-up of the Soviet Union.
Moscow officially recognized their independence after fighting a five-day war against Georgia in August 2008.
Following the 2008 conflict, Russia deployed thousands of troops in the two regions. Georgia and the West condemned the move as an illegal occupation.
More recently, Moscow took further measures to integrate them, proposing "alliance and integration" agreements that would considerably strengthen their ties with Russia.
The agreements provide for the creation of joint Russian and Abkhazian military forces.
Tbilisi condemned the move as "yet another step against Georgia's sovereignty and territorial integrity."
The November 15 protest was held amid a looming political crisis sparked by the recent departure of three cabinet ministers responsible for closer integration with the EU and NATO.