The 28-year-old replaces comedian Amy Schumer, who dropped out of the project in 2017.
The Mary Queen of Scots and I, Tonya star will also produce the movie via her production company, LuckyChap Entertainment.
“Playing with Barbie promotes confidence, curiosity and communication throughout a child’s journey to self-discovery,” Robbie said.
“Over the brand’s almost 60 years, Barbie has empowered kids to imagine themselves in aspirational roles from a princess to president. I’m so honoured to take on this role and produce a film that I believe will have a tremendously positive impact on children and audiences worldwide.
“I can’t imagine better partners than Warner Bros and Mattel to bring this film to the big screen.”
The film, which has yet to have a title, a director or a release date, marks the first collaboration between the two US companies.
“Margot is the ideal producer and actress to bring Barbie to life on screen in a fresh and relevant way for today’s audiences.” said Toby Emmerich of Warner Bros.
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