Comedian Volodymyr Zelenskiy is in the lead in Ukraine's presidential election, an exit poll has indicated.

Figures released after voting stations closed indicated that Mr Zelenskiy had received about 30.4 per cent of the nationwide vote, followed by incumbent president Petro Poroshenko with 17.8 per cent and former prime minister Yulia Tymoshenko with 14.2 per cent support.

Despite Mr Zelenskiy's lead, his support is well short of the majority needed to win in the first round.

The poll, which was conducted by the Kiev International Institute of Sociology and public opinion organisation the Razumkov Centre, was based on nearly 18,000 responses to questions posed at some 400 polling places as of 6pm, two hours before the polls closed.

The poll claims a margin of error of 2.5 percentage points.

A run-off between the top two candidates in the race will take place on April 21.