Sylvie Testud was born on January 17, 1971, in Lyon, France. Her parents separated when she was just two years old, and she was raised by her mother, an accountant, in the Lyon district of Croix-Rousse. During her youth, Testud developed a passion for the cinema, identifying with complex characters like Charlotte Gainsbourg's portrayal of a teenager in L'Effrontée.
Testud's fascination with acting led her to take drama lessons in Lyon with Christian Taponard, before moving to Paris in 1989 to study history and attend the Cours Florent and the National Conservatory of Dramatic Art for three years, where she was taught by Jacques Lassalle and Catherine Hiegel.
She began her acting career in the early 1990s, landing small roles in films such as The Story of the Boy Who Wanted to Be Kissed by Philippe Harel (1994),Le Plus Bel Age... by Didier Haudepin (1995),and Love, etc. by Marion Vernoux (1996).
Testud's breakthrough role came in 1997 with the German film Beyond Silence by Caroline Link, for which she learned German, the clarinet, and sign language. Her performance earned her the German Film Prize for Best Actress, equivalent to the César for Best Actress.
In 1998, she played her first major role in French cinema in Karnaval, the debut feature film by Thomas Vincent, for which she was nominated for the César for Best Female Hope and received the Michael Simon Prize. This marked the beginning of an important acting career, with a focus on auteur cinema.
Testud's subsequent performances earned her critical acclaim and numerous award nominations. In 2000, her role in La Captive by Chantal Akerman earned her a nomination for Best Actress at the European Film Prize. In 2001, she won the César for Best Female Hope for her portrayal of Christine Papin in Les Blessures assassines by Jean-Pierre Denis, based on a true news story from 1933.
Throughout her career, Testud has demonstrated her versatility and range as an actress, taking on complex and challenging roles that showcase her talent and dedication to her craft.