Keira has recorded a TV commercial for charity WomensAid, to highlight domestic abuse among women.
In the disturbing two-minute commercial, made by Joe Wright, who directed the star in the films Atonement and Pride and Prejudice, Knightley is seen being attacked by her partner, who accuses her of having a relationship with a co-star.
"I wanted to take part in this advert for Women's Aid because while domestic violence exists in every section of society we rarely hear about it," said Knightley.
"Domestic violence affects one in four women at some point in their lifetime and kills two women every week."
The extended ad will debut on April 6 in 15-plus films in cinemas nationwide. Check out her shocking new commercial below and let us know your thoughts...