Hollywood comedian Robin Williams has ruled out running for US president, joking he wouldn't get the vote of "lesbian vegetarians".

The Oscar winner plays an outspoken and honest talk show host who lands the job of American leader in new movie Man Of The Year.

And Williams wishes the US would vote in someone of a similar integrity as president.

He says, "Oh please, no. I don't want to be in office. I've seen what it does to people. I'd rather be a comic. And I'm not sure I appeal to lesbian vegetarians.

"But we do need someone with integrity, honesty, passion and humour."