Méril is descended by her father from the Russian princely house Gagarin and by her mother from a Ukrainian noble family. She appeared in 125 films between 1959 and 2012, including films directed by Jean-Luc Godard (Une femme mariée), Luis Buñuel (Belle de jour), and Rainer Werner Fassbinder (Chinese Roulette).
She also appeared in the Quebec television series Lance et Compte. She is perhaps best known for her roles as Helga Ulmann in Dario Argento's Deep Red and in Aldo Lado's Night Train Murders (1975).
