Humanity will prevail," Zelenskiy said, leading a ceremony at which the Ukrainian flag was raised in Bucha.
Zelenskiy described Bucha as a "symbol of the atrocities" of Russian occupying forces.
Fighting rages on in the east and south of Ukraine, where Russian forces hold swathes of territory captured after they invaded on Feb. 24, 2022.
Ukrainian forces have dug in and held out for now in the city of Bakhmut and are expected to launch a counteroffensive soon.
This is part of Russia's planned strategy to destroy Ukraine as a state and Ukrainians as a nation," he said.