Following the death of her father while she was still a young girl, she worked to support her family.

Since her appearance in Louis Malle's 1974 film Lacombe Lucien, she has been cast in many roles in over five decades.

Her first appearance in a U.S. movie was in Apocalypse Now (1979), but her scenes—a long sequence involving French former colonists—were eventually cut from the film and restored in 2001 in the Redux version.

In France, Clément made her stage debut in 1988 with The Singular Life of Albert Nobbs, adapted from George Moore's short story, and won an acting prize from The French Association of Theatre critics.

She has been in several plays, including Les Eaux et Forêts and La Dame aux Camélias, for which she was nominated for the Molière Awards (the equivalent of the American Tonys).