Bérénice Marlohe was unveiled alongside her co-star Daniel Craig, who plays 007, at a press conference in London to launch the 23rd film in the Bond series, named Skyfall.
The role is a huge break for Marlohe who is little known even in her own country. She is best known for roles in a number of television series and has also appeared in some advertising campaigns, including one for the Renault-owned Romanian Dacia car brand.
A director who has worked with Marlohe in the past said he "wasn't surprised" to discover she would be taking on such an important role.
"She is bilingual and has an exotic beauty," Vincent Giovanni told daily newspaper Le Parisien. "She has lots of charisma and is very eye-catching."
The newspaper reported that Marlohe got the role after a friend told her auditions were taking place.
"After the audition I had to wait several days to find out I'd be part of this film. Now that we're just four days from shooting I'm really excited," she said.
France has a proud history of supplying Bond girls to challenge the British secret agent. Others include Claudine Auger, Carole Bouquet, Corinne Cléry, Sophie Marceau and Eva Green, who appeared in Casino Royale.
"It's absolutely amazing because James Bond movies are such huge and fantastic movies and we have a wonderful cast and director," she said at the press conference. "I'm very thrilled and honoured to be part of it."
Other stars joining the cast include Dame Judi Dench, who will play Bond's boss M for the seventh time, and Javier Barden, who will play the villain.
Bérénice Marlohe in a commercial for the Dacia Duster:
Bérénice Marlohe speaking at Thursday's press conference: