The president delivered a powerful speech in a recorded message, in which he directly addressed the crowd of celebrity musicians, referencing Russia's war in Ukraine.
"What's more opposite to music?" President Zelenskyy said.
"The silence of ruined cities and killed people.
"The war doesn't let us choose who survives and who stays in eternal silence."
He delivered the speech directly to camera, speaking about the musicians of Ukraine, who are currently fighting a war, not performing on stage.
"Our musicians wear body armour instead of tuxedos," he said. "They sing to the wounded in hospitals, even to those who can't hear them. But the music will break through.
"We defend our freedom to live, to love, to sound."
"On our land, we are fighting Russia, which brings horrible silence with its bombs," President Zelenskyy said, before urging the room to "fill the silence with [their] music.
"Support us in any way you can, but not with your silence. Fill the silence with music," he said.
The award ceremony appearance came after rumours of a video message at the 94th Academy Awards on March 27, which did not come to fruition.
The message was played ahead of John Legend's performance of Free, which was part of a tribute to Ukraine. Legend was joined on stage by Ukrainian musicians Mika Newton and Suzanna Iglidan.
Part of the performance included Ukrainian poet Lyuba Yakimchuk reading a poem, with Legend playing the piano to accompany.
Legend was flanked by performers wearing yellow and blue, the colours of the Ukrainian flag.
The performance ended with information detailing ways to donate to a charity helping Ukrainian refugees.
The line-up for the two-hour Concert for Ukraine in Birmingham, UK, also featured Ukrainian singer Jamala, who won the 2016 Eurovision Song Contest, music veterans Nile Rodgers & Chic, as well as groups Snow Patrol and Manic Street Preachers.