Olivia Wilde thinks choosing not to cast a vote in the upcoming American presidential election is "crazy".

Election Day will be held on November 6.

A staunch patriot, Olivia believes it's vital that everyone reach the ballot box next month.

"Less than 50 per cent of young people voted in the last election. That's crazy," she told MTV News.

"People need to get out and vote. Young people, you cannot complain unless you've voted. I don't want to hear any b***hing in the next four years if you haven't voted."

The race between presidential candidate John McCain and current US president Barack Obama was close four years ago.

Olivia implores people to realise how far their vote goes.

"When North Carolina was won by Barack Obama [in 2008] with only 14,000 votes, it gives you an idea of how much your vote actually counts. It matters,".

"To young people who are voting for the first time, who have come up in a tricky economic climate, that's specifically why you have to get out and vote. Shape your future. It's absolutely imperative that you participate."