Jewish actor with no political experience expected to take 73 percent of the popular vote; incumbent Poroshenko concedes defeat.
An investigative TV report at the start of the year meanwhile accused Zelensky of having commercial relations with Russia.
Following the broadcast, Zelensky confirmed he had shares in a Cypriot company that owns a Russian group and promised to sell them.
Zelensky has insisted that as leader he would demand Putin end Moscow’s occupation of Ukrainian territory and pay compensation for the conflict.
And he has pledged to keep Kiev on the pro-Western course it charted under Poroshenko.
The diminutive performer, from the industrial city of Krivy Rig in central Ukraine, is a dollar millionaire.