One of the first groups in the world dedicated specifically to contemporary music, the Ensemble Intercontemporain in Paris remains among the most influential. The Ensemble was led by avant-garde composer and conductor Pierre Boulez for much of his life.

Boulez founded the Ensemble Intercontemporain in Paris in 1976. At the time, although the London Sinfonietta already pursued a focus on 20th century music, the idea of a performance organization devoted to new music may have been unique. The group had, and still has, 31 players, a set of forces derived from those needed to perform key chamber works by Stravinsky, Webern, Schoenberg, and Boulez himself. The Ensemble Intercontemporain developed in tandem with IRCAM (Institut de Recherche et de Coordination Acoustique/Musique), a research and performance venue located at the Georges Pompidou Center in Paris, and in its early years, it often performed at IRCAM. Boulez held the position of president of the Ensemble Intercontemporain; he appointed a series of music directors, beginning with Péter Eötvös in 1979, but during Boulez's lifetime, the Ensemble was always closely identified with him. Thanks to his celebrity, the Ensemble Intercontemporain soon began a high-flying international recording career; in 1982, the group released an album of works by Berg and Stravinsky on the Deutsche Grammophon label. Although its programming and recordings are primarily oriented toward new works, the Ensemble also performs classic 20th century music. Later music directors have included David Robertson (1992-2000), Susanna Mälkki (2006-2013, the group's first female director), and Pierre Bleuse, who is set to become music director in 2023.

In 1995, the Ensemble Intercontemporain moved to the Cité de la Musique complex in Paris and then, in 2013, to the new and nearby Philharmonie de Paris. With a repertory of some 2,000 contemporary works to draw from (many commissioned by the Ensemble itself), the group gives about 30 concerts annually in Paris and also tours frequently; it has visited North and South America, Russia, East Asia, and Australia as well as many European capitals. It also performs in smaller subgroups drawn from the full ensemble, often billed as Soloists of the Ensemble InterContemporain. The Ensemble Intercontemporain has issued some 30 albums, on such labels as Kairos, Wergo, and Alpha, in addition to having an ongoing relationship with Deutsche Grammophon. In 2022, Ensemble Intercontemporain moved to Nonesuch for the album Reich/Richter. ~ James Manheim, Rovi