Gérard Grisey (/ˈɡrɪzi/; French: [ɡʁizɛ]; 17 June 1946 – 11 November 1998) was a twentieth-century French composer of contemporary classical music. His work is often associated with the Spectralist Movement in music, of which he was a major pioneer.

Gérard Grisey was born in Belfort, France, on 17 June 1946 (Anderson 1998). From a very young age, Grisey demonstrated enormous interest and talent in music composition and study, writing his first essay on music when he wave 9 years old (Anon. 2019). He studied at the conservatory in Trossingen in Germany from 1963 to 1965 (Anon. n.d.) before entering the Conservatoire National Supérieur de Musique where he studied with Olivier Messiaen from 1965 to 1967 and again from 1968 to 1972, while also working with Henri Dutilleux at the Ecole Normale de Musique in 1968 (Anderson 2001). He won prizes for piano accompaniment, harmony, counterpoint, fugue, and composition at the Conservatoire under Messiaen's guidance (Anon. n.d.). He also studied electroacoustics with Jean-Étienne Marie in 1969, composition with Karlheinz Stockhausen, Iannis Xenakis and György Ligeti at the Darmstädter Ferienkurse in 1972, and acoustics with Emile Leipp ^[10] at the Faculté des Sciences in 1974. Other studies were undertaken in the summer of 1969 at the Accademia Chigiana in Siena (Anon. n.d.).

Grisey won the highly coveted Prix de Rome, enabling him to stay at the Villa Medici in Rome from 1972 to 1974 (Anderson 1998). While there he became friends with Tristan Murail, with whom he founded the group L'Itinéraire in 1973 along with Roger Tessier and Michaël Lévinas, later to be joined by Hugues Dufourt. In 1974–75, he studied acoustics with Emile Leipp at the Paris VI University (Anderson 2001; Anon. n.d.), and in 1980 became a trainee at the IRCAM (Institut de Recherche et Coordination Acoustique/Musique) in the computer music course organized by David Wessel and Marc Battier. During the same year, Grisey went to Berlin as a guest of the D.A.A.D. (Berliner Künstlerprogramm des DAAD) program. He subsequently left for the University of California, Berkeley, where he was appointed professor of theory and composition for the years 1982–1985 (Anderson 1998) or until 1986 (Anderson 2001). After returning to Europe, he took up the role of professor of orchestration and composition at the Conservatoire de Paris from 1987 until his death (Anderson 1998; Anderson 2001), while also holding numerous composition seminars in France (Centre Acanthes, Lyon, Paris) and abroad (Darmstadt, Freiburg, Milan, Reggio Emilia, Oslo, Helsinki, Malmö, Göteborg, Los Angeles, Stanford, London, Moscow, Madrid, etc.) For notable pupils See: List of music students by teacher: G to J#Gérard Grisey.

Gérard Grisey died at the age of 52 in Paris on 11 November 1998 due to a ruptured aneurysm (Anderson 2001).

Grisey's music is often considered to belong to the genre of spectral music, which he is credited with founding along with fellow composer Tristan Murail, although he later disowned the label in interviews and writings. According to Tom Service (2013), "His achievement has often been reduced to yet another of new music's fetishistic labels, "spectralism" – a category that Grisey had rejected by the end of his life."

Nonetheless, he spent much of his career exploring the spectrum of tone colour between harmonic overtones and noise. In addition, he was fascinated by musical processes which unfold slowly, and he made musical time a major element of many of his pieces.

He expressed the opinion that: "We are musicians and our model is sound not literature, sound not mathematics, sound not theatre, visual arts, quantum physics, geology, astrology or acupuncture" (Fineberg 2006, p. 105).