Born in a family of artists, she trained at the Cours Florent, then at the Conservatoire National d'Art Dramatique of Paris from 1989 to 1992. She burst onto the screen in 1994 in Éric Rochant's Les Patriotes, which earned her the Prix Romy-Schneider, and a nomination for the César for Best Newcomer, which she won in 1996 for En avoir (ou pas) by Laetitia Masson. She also won the Molière for Best Theatrical Revelation in 1997 for Le Roman de Lulu.

Since then, carried away by what she calls her "sacred fire", she never ceased to play roles in all registers, moving gracefully and whimsically from comedy to drama, showing absolute freedom in her choices. She has worked with Jacques Audiard, Benoit Jacquot, Pascal Bonitzer, Claude Miller, Alain Resnais, Nicole Garcia, Philippe Le Guay, Stéphane Brizé, André Téchiné, Maïwenn, Jeanne Herry and Bruno Podalydès. Often nominated for the César for Best Actress, she won it in 2014 for Albert Dupontel's 9 Mois ferme. She also stepped behind the camera in 2016 for a short film, Bonne Figure, before directing in 2021, Une jeune fille qui va bien, a film that testifies to her great sensitivity and commitment. In addition to her work on the big screen, she has also made a name for herself as a singer, taking part on several occasions in the Enfoirés tour.