The British-born model is best known for appearing in the controversial music video for Robin Thicke's Blurred Lines, which has racked up more than 174 million views on YouTube since debuting in March this year.
Ratajkowski will play Andie, a college student having an affair with Ben Affleck's Nick Dunne, reports The Wrap.
Gone Girl marks Ratajkowski's film acting debut.
20th Century Fox's big screen adaptation of Gillian Flynn's novel will star Rosamund Pike as Amy Dunne, the wife of Nick, who vanishes on their fifth wedding anniversary.
Tyler Perry will play lawyer Tanner Bolt, while Neil Patrick Harris has been cast as Amy's ex-boyfriend Desi Collins. Carrie Coon, Patrick Fugit and Kim Dickens also star.
Reese Witherspoon is producing the film alongside Bruna Papandrea and Leslie Dixon.