It spotlights her ruthless and manipulative character Crystal.
The film centres around Ryan Gosling as Julian, a retired boxer and gangster who lives in Bangkok.
When his brother is killed by a brutal Thai policeman, his mother (Scott Thomas) forces him to seek revenge.
Only God Forgives reunites Gosling with Drive director Nicolas Winding Refn.
Scott Thomas has admitted that the film is "really not [her] thing".
The violent movie divided critics when it premiered at the Cannes Film Festival in May.
Only God Forgives will arrive in US cinemas on July 19 and in the UK on August 2.
Watch Ryan Gosling discuss Only God Forgives with Digital Spy below: