Kelly Marcel (born 10 January 1974) is an English filmmaker and former actress.

After working as a child actor in the United Kingdom, Marcel had her breakout as a screenwriter in Hollywood when her script for Saving Mr. Banks made the 2011 Black List and was quickly acquired by Disney, which released the film in 2013. She is also known for writing the 2015 film adaptation of E. L. James' Fifty Shades of Grey and the Sony's Spider-Man Universe film Venom (2018) as well as its sequels Venom: Let There Be Carnage (2021) and Venom: The Last Dance (2024), the latter of which she directed in her directorial debut.