Louis Sclavis is a clarinettist, bass clarinettist, soprano saxophonist and composer from Lyon, a figure of French improvised music since the second half of the 1970s and, since 1992, a leader on ECM. He was born on February 2, 1953, in the 4th arrondissement of Lyon, into a modest family: his mother was a seamstress and his father a photographer. He started music theory at seven and the clarinet at nine or ten, first with an amateur teacher and in the wind band of his neighbourhood, then at an annex of the Lyon conservatoire. As a teenager he played in a small New Orleans band, and between the ages of 18 and 22 he alternated odd jobs with his first paid work as a composer and musician for Lyon theatre companies and dance troupes. The bass clarinet came into his playing in those years. He has named the Living Theatre and Bread and Puppet, and the records of Soft Machine, Sun Ra and the Art Ensemble of Chicago, as influences from that period.

He turned professional in 1975 with the Free Jazz Workshop, which became the Workshop de Lyon, and recorded with the singer Colette Magny on Transit the same year. In 1977 he was one of the founders of ARFI (Association à la Recherche d'un Folklore Imaginaire), the Lyon collective, and played and recorded with its Marvelous Band, with La Marmite Infernale, and with the songwriter Steve Waring. His first record under his own name, Ad Augusta Per Angustia (Nato), is dated 1981. In the early 1980s he also played with Michel Portal, in the company of Bernard Lubat, in Chris McGregor's Brotherhood of Breath (Yes Please, recorded at Angoulême in 1981) and in the quartet of Henri Texier, with whom he made La Compañera (1983). He left the Workshop de Lyon and ARFI in 1986.

From 1984 and 1985 he led his own groups: Clarinettes (IDA, recorded in Lyon in September 1984 and January 1985), then a trio with the pianist François Raulin and the drummer Christian Ville that grew into a quartet with the bassist Bruno Chevillon and a quintet with the violinist Dominique Pifarély. That quintet made Chine (IDA, 1987) and, as a septet with the trombonist Yves Robert, the guitarist Philippe Deschepper and the tuba player Michel Godard, Chamber Music (IDA, 1989). He won the Académie du Jazz's Prix Django-Reinhardt for best French jazz musician in 1988, the first prize of the Barcelona Biennale in 1989, the British Jazz Award at the Midem for best foreign artist in 1990 and 1991, and a Django d'or for best French jazz album in 1993. In Berlin he recorded for FMP with the saxophonists Evan Parker, Hans Koch and Wolfgang Fuchs (Duets, Dithyrambisch, recorded live in July 1989) and with the cellist Ernst Reijseger (Et on ne parle pas du temps, recorded live in July 1994).

Rouge, recorded in Oslo in September 1991 and released by ECM in 1992, began his long relationship with that label. Acoustic Quartet (1994) added the guitarist Marc Ducret to Pifarély and Chevillon, and Les Violences de Rameau (1996) turned Jean-Philippe Rameau's opera Les Boréades into music for a sextet. At the same time he worked with Henri Texier and the drummer Aldo Romano in a trio tied to the photographs of Guy Le Querrec, which recorded Carnet de routes (1995), Suite africaine (1999) and African Flashback (2005) for Label Bleu and, with the guests Enrico Rava, Nguyên Lê and Bojan Z, 3+3 (2012). The Louis Sclavis Trio with Chevillon and the drummer François Merville, created in Villeurbanne in January 1994, made Ceux qui veillent la nuit (Label Bleu, 1996), and Danses et autres scènes (Label Bleu, 1997) gathered a larger group of players, among them the accordionist Richard Galliano.

He also became a film composer. He wrote the music for Bertrand Tavernier's Ça commence aujourd'hui (1999), and for ECM he scored the restored 1929 silent film Dans la nuit by Charles Vanel (recorded in October 2000, released in 2002). In 2022 the Angoulême francophone film festival gave him its Valois for film music for Le Sixième enfant. Napoli's Walls (ECM, 2003) paired him with the cellist Vincent Courtois, the guitarist Hasse Poulsen and the trumpeter Médéric Collignon; L'Imparfait des langues (2007) was commissioned by the Printemps des Arts de Monte-Carlo; Lost on the Way (2009) follows the Odyssey. He received the SACEM's Grand Prix in 2009. Outside his own bands he recorded Bow River Falls (Koch, 2004) with the trumpeter Dave Douglas at the Banff workshop in June 2003, a duo with the Japanese-born pianist Aki Takase (Yokohama, Intakt, 2009), the Eldorado Trio with the pianist Craig Taborn and the drummer Tom Rainey (Clean Feed, 2010), and several records with the guitarist Fred Frith and the percussionist Jean-Pierre Drouet.

The groups of his later ECM years were built around the pianist Benjamin Moussay: the Atlas Trio with the guitarist Gilles Coronado (Sources, 2012), the quartet that added the percussionist Keyvan Chemirani (Silk and Salt Melodies, 2014), and the quartet with the bassist Sarah Murcia and the drummer Christophe Lavergne (Characters on a Wall, 2019). Ida Lupino (2016) was made with the pianist Giovanni Guidi, the trombonist Gianluca Petrella and the drummer Gerald Cleaver, and Asian Fields Variations (2017) with Pifarély and Courtois. Unfolding, a clarinet and piano duo album with Moussay recorded in March 2024, came out on ECM in September 2024 and he is listed with Moussay for concerts at Unterfahrt in Munich on January 23, 2027 and at Jazz im Theater in Salzburg on January 24, 2027. His newest quintet, with Murcia, Moussay, Lavergne and the trumpeter Olivier Laisney, recorded India in November 2024 (Yolk Records, released October 17, 2025). On October 16, 2026 the Italian label Da Vinci Jazz issued Perdu dans un rêve, on which he plays bass clarinet with the drummer Enzo Lanzo and the guitarist Livio Bartolo.

English Wikipedia places him in avant-garde jazz, free jazz, free improvisation and contemporary classical music, and notes that he was one of the first to combine jazz with French folk music, most prominently with the hurdy-gurdy player Valentin Clastrier. His records move between those poles: through-composed pieces for chamber groups (Chamber Music, Les Violences de Rameau, the saxophone quartet pieces of L'Engrenage with the Quatuor Habanera), free improvisation with European players (Evan Parker, Hans Koch, Wolfgang Fuchs, Ernst Reijseger, Fred Frith), tributes (Ellington on the Air, 1992, a sextet re-reading of Duke Ellington), and writing for the screen, the stage and dance. The ARFI idea of an imaginary folklore runs through his tune writing, and he names the free theatre of the early 1970s, Soft Machine, Sun Ra and the Art Ensemble of Chicago as his points of departure. Bass clarinet is his signature sound, with the clarinet and the soprano saxophone beside it, and on records he is also credited on baritone saxophone (Napoli's Walls), flute (Danses et autres scènes), melodica, harmonica and mbira (Langues et lueurs). On several ECM records he also supplies the liner notes and the cover photograph.