Margot Robbie will play Harley Quinn in new movie 'Suicide Squad'.

The 24-year-old actress will play the role of The Joker's accomplice in the much-anticipated new film, which is set to open in 2016, Collider reports.

Margot - who starred in 'The Wolf of Wall Street' last year alongside Leonardo DiCaprio and is currently filming 'Tarzan', in which she's playing the role of Jane - has reportedly seen off competition from British model Cara Delevingne for the sought-after part.

Cara, 22, was heavily linked to the role after she posted a picture of herself on Instagram dressed as the character, but it appears Margot has landed the part.

The news comes shortly after it was reported that Jared Leto is set to star as The Joker in 'Suicide Squad'.

According to TheWrap, the 42-year-old musician-actor is in talks with Warner Brothers about playing the iconic Batman character in their new film.

A source also revealed Ryan Gosling was invited to play The Joker, but declined as he was unwilling to sign up to multiple sequels.

Tom Hardy and Will Smith are also said to be in discussions with the film's director David Ayer.