Mr Zelenskyy appeared on video as he addressed thousands in several European cities including Paris, Prague, Lyon and Frankfurt, declaring all who were watching were Ukrainians today.
He asked the big crowds not to be silent about what is going on in his country.
“Don’t turn a blind eye on this,” he said. “Come out and support Ukraine as much as you can,” he said though a translator.
“If we fall, you will fall,” he said.
“And if we win, and I’m sure we’ll win, this will be the victory of the whole democratic world, this will be the victory of our freedom, this will be the victory of light over darkness, of freedom over slavery. And if we win we will become as blossoming as Europe. And Europe will be flourishing more than ever,” he said.
“All of you are Ukrainians today, thank you for this.”
The president's use of social media has helped him thwart Russian disinformation claiming he is dead or has fled.
Russia has also struggled to control information coming out of Ukraine.
The new laws effectively caused the last few independent media stations to close.
It also forced the BBC and other global media brands to suspend their operations in Moscow.
On Friday Russia also blocked access to Facebook, cutting tens of millions of people off from their accounts.
Mr Zelenskyy's speech came amid the outcry over Russia's attack on Europe's largest nuclear power plant.
Nuclear officials from Sweden to China said no radiation spikes had been reported, but many nations still reacted with anger.
Ukraine’s state nuclear plant operator Enerhoatom said three Ukrainian soldiers were killed and two wounded.
In an emotional speech in the middle of the night, Mr Zelenskyy said he feared an explosion that would be “the end for everyone. The end for Europe. The evacuation of Europe”.
But most experts saw nothing to indicate an impending disaster.
With the invasion in its second week, another round of talks between Russia and Ukraine yielded a tentative agreement to set up safe corridors to evacuate citizens and deliver humanitarian aid to the country, overturned by a war that has sent more than one million fleeing over the border and countless others sheltering underground.