The singer's maternal grandfather built "cabanons" in the resort of Soulac-sur-mer, in Gironde in 1886. During the Second World War, the artist's Father, an industry man, was captured and detained as a prisoner of war in Germany until the liberation in May 1945. Marie, her sister Alexandra and their mother knew a period of many hardships. At the age of three Marie suffered a sexual trauma which affected her for a long time. During the war, the Doumenachs found shelter at Cahors and in the province of their ancestors Ariège, in the village Lavelanet. After the war, the family moved to Valenciennes where the Father led a factory for railway utensils. Later they settled in Paris. After becoming more religious and having considered becoming a nun, Marie continued her secondary studies at the Lycee La Fontaine in Paris. There she began to show interest for the dramatic arts and her first experiences in this domain proved to be therapeutically useful for her through their cathartic effect.
Her career began accidentally in 1959 when she replaced her sister at the last minute in a French radio talent contest Naissance d'une étoile (birth of a star) and won. Director Louis Malle then cast the young starlet in the film he was shooting at the time, Liberté, a project he finally abandoned, making Laforêt's first appearance on screen opposite actor Alain Delon in René Clément's 1960 drama Plein Soleil.
She also recorded some rock songs in the 1960s, her most famous being "Marie-douceur, Marie-colère", a 1966 cover of the Rolling Stones hit "Paint It Black". Another popular recording was 1965's girl group-style "A demain, my darling", known by English-speakers as "The Sha La La Song" written by Marianne Faithfull on her debut eponymous album.
In her second film, Saint Tropezi Blues, accompanied by a young Jacques Higelin at the guitar, she sang the title song and immediately started releasing singles, her first hit being 1963's Les Vendanges de l'Amour. Her songs offered a more mature, poetic, tender alternative to the light, teenage yé-yé tunes charting in France at the time. Her melodies borrowed more from exotic folk music, especially South American and Eastern European, than from contemporary American and British pop acts. Laforêt worked with many important French composers, Musicians and lyricists, such as André Popp and Pierre Cour, who provided her with a panoply of colorful, sophisticated orchestral arrangements, featuring dozens of musical instruments and creating a variety of sounds, sometimes almost Medieval, Renaissance or Baroque, other times quite modern and innovative.
The quiet, bittersweet and minimally arranged ballad "Je voudrais tant que tu comprennes" (1966), composed by Francis Lai, is a Marie Laforêt favorite. Homage was paid to the song in the 1980s when French pop superstar Mylène Farmer added it to her own concert repertoire.
Some of her most memorable pop songs are those written or arranged by French Composer André Popp, such as "Entre toi et moi", "L'amour en fleurs", "Les noces de campagne", "Mon amour, mon ami", and "Manchester et Liverpool". The melody of the latter song gained fame in the former Soviet Union as the background music to the Vremya television news programme's weather forecast in the 1970s.
The 1973 hit "Viens, viens" was a cover version of a German song "Rain, Rain, Rain" performed by Simon Butterfly.
Marie's 1977 hit "Il a neigé sur Yesterday", perhaps her most well-known recording, was penned by musician Jean-Claude Petit, and lyricist Michel Jourdan, (famous for his work with Dalida, Nana Mouskouri, Michel Fugain and Mike Brant) and who had written the words for earlier Laforêt songs, such as "Les vendanges de l'amour" and "L'orage".
In the 1980s, Marie concentrated on her acting career, appearing in a few French and Italian films. Some music singles were eventually released, but were not popular. She made a comeback, however, in 1993 with her final album, for which she wrote the lyrics. In the 1990s, she again continued to work as an Actress, both on screen and on stage. She has performed in a number of plays in Paris over the years, acclaimed by audiences and critics alike. In September 2005, she sang once again, going on tour in France for the first time since 1972. Every concert was sold out. Laforêt still currently resides in Geneva and has obtained Swiss citizenship.
Doumenach, her last name, is Catalan in origin – Domènec in Catalan. Her birth name Maïtena Marie Brigitte Doumenach, and her repertoire which included pieces inspired from the world folklore, have led to speculation of an Armenian origin of her parents. The singer herself used to define herself sometimes as "ariégeoise", i.e. from the region of Ariège in the south of France.