Guy Ritchie will direct the medieval epic.
In the classic tale, Guinevere is the young lover of King Arthur before she later betrays him for the knight Lancelot. Ritchie’s film is expected to focus on Arthur’s earlier days.
Hunnam stars in the film with Idris Elba playing his right hand man, Bedivere.
Joby Harold penned the script and is producing with Akiva Goldsman and Tory Tunnell.
“King Arthur” hits theaters July 22, 2016.
Berges-Frisbey beat out a handful of ladies who were chasing the role including Elizabeth Olsen, Felicity Jones and Alicia Vikander.
The CAA-repped actress has also appeared in “Pirates of the Caribbean: On Stranger Tides.”