Denis Dufour was born in France in 1953. He entered the Conservatoire National de Région (CNR) in Lyon in 1972, and then from 1974-1979 studied at the Conservatoire de Paris (CNSMDP) with Michel Philippot and Ivo Malec (instrumental composition), Claude Ballif (analysis), and Guy Reibel and Pierre Schaeffer (electroacoustic composition). A researcher and a staff member of the INA-GRM starting in 1976, he was a teaching assistant in the electroacoustics class at the Conservatoire de Paris (CNSMDP). In 1977, he founded the TM+ Ensemble, and was the impetus for the creation of a major corpus of mixed and "live electronic" compositions. He was a studio assistant to Pierre Schaeffer, Marcel Landowski, Guy Reibel, and François Bayle, and participated in the design and building of the Acousmographe, as well as helping to organize conferences and seminars. He also contributed to the building of the SYTER system, for which he composed the first piece for instruments and real-time digital processing, Ourlé du lac (1984), performed during the 1984 ICMC in Paris, organized by the IRCAM.

In 1980, he created an acousmatic and instrumental composition class at the CNR de Lyon, which he taught until 1995. He launched the Acore concerts in 1982, organizing a regular cycle of performances each year. In 1984, he helped to found the Quark composers' collective, and hosted the Rencontres de Crest sur l'Art Acousmatique from 1989 to 1994. In 1993, he created the Festival Futura (an international festival for acousmatics and related arts) in Crest (Drôme), France. In 1997, he launched Motus, which organizes concerts and events (such as Odysson, Acousma-rave, etc.) and manages the world's largest privately-owned sound projection system and runs a recording label dedicated to contemporary music (acousmatic and instrumental). In 2004, he founded the Syntax ensemble with five other professors at the CNR Perpignan-Méditerranée, which has its own acousmonium. In 2017, he co-founded the duo HD, which works in performance and conceptual events.

In 1995, he took over the composition class at the Conservatoire de Perpignan, where he organizes six concerts per year. Starting in 1997, he organized Les Empreintes, an annual lecture series given by invited composers at the INA-GRM, as well as L'Atelier, whose purpose is to foster exchanges between the GRM and the music world. He also created a database to manage the works and documents of the Acousmathèque. He left the GRM in 2000.

In 2002, he founded the first summer course in acousmatic performance in Crest, which brings together a dozen students from around the world for over a week each year. In 2007, he designed and taught a class on electroacoustic composition and sound design at the Conservatoire à Rayonnement Régional de Paris. Two years later, he became professor of musical creation in electroacoustic composition at the Pôle supérieur d’Enseignement Artistique Paris in Boulogne-Billancourt.

Dufour has been composing since 1976, and is the author of numerous instrumental works (orchestral, chamber, vocal) and electroacoustic pieces, where, with the fluidity of baroque phrasing, he plays wth the mobility of figures, the exploration of new morphologies (from work with different media), with colors and interactions, in a style whose language and lyricism are strongly his own. In his latest acousmatic pieces, he has reintroduced human voices and their dramatic and narrative impact into the highly formal universe of acousmatic music, which he has transformed into a space for a new form of theatricality. Denis Dufour is one of a handful of French compsers working with equal enthusiasm in both the instrumental and acousmatic worlds, for which he writes works of equal stylistic maturity and iconoclastic, rigorous fervor.

Denis Dufour promotes a concept of spatialization performed in sound works on acousmonium or by loudspeaker orchestra; for these he has composed numerous pieces including Bocalises, grande suite (1978), Entre dames (1982), Messe à l'usage des vieillards (1987), Les Joueurs de sons (1999), La Nuit du Dibdak (2000), Caravaggio (2000), and Volver (2012).

In 2009, he was awarded the SACEM prize for best electroacoustic composition for PH 27-80 (2008).

Since 2013, his instrumental and mixed pieces have been published by Maison Ona.