More than 5,000 people protested in Athens on Sunday, police said, calling for an end to the "massacre" of Palestinians in the Gaza Strip.
"We are fighting for the peace of people," Athens News Agency quoted demonstrators as chanting through loudhailers.
"Stop the massacre of the Palestinian people in Gaza," they shouted.
Hamas militants launched a surprise attack on Israel on October 7, killing at least 1,400 people, mostly civilians, according to Israeli officials.
Since the attack, the health ministry in the Hamas-run Gaza Strip says more than 8,000 Palestinians have been killed -- half of them children -- by Israel's relentless retaliatory bombardments.
The Athens demonstrators branded Israel a "murderous state" and also denounced the Greek government for abstaining at Friday's UN vote for an immediate humanitarian ceasefire in Gaza.
Tens of thousands of pro-Palestinian protesters marched in Britain on Saturday calling for a ceasefire as Israel's army intensified its assault on Gaza.
Thousands more demonstrated in France and Switzerland, as well as in New York.
In Athens, the protesters marched to Israel's embassy in the Greek capital's Psychiko's suburb.
No trouble was reported during the demonstration.
Ambassador from the Palestinian Authority Youssef Dorchom attended the protest as did a large delegation from Greece's KKE Communist Party.
