Philippe Leroux was born in France in 1959. He began his studies at the Conservatoire de Paris (CNSMDP) in 1978, studying with Ivo Malec, Claude Ballif, Pierre Schaeffer, and Guy Reibel, and earning three premiers prix (highest honors). During this time, he also studied with Olivier Messiaen, Franco Donatoni, Betsy Jolas, Jean-Claude Eloy, and Iannis Xenakis. In 1993, he was a fellow at the Villa Medici, where he stayed until October 1995.

He has composed nearly eighty pieces, including symphonic, acousmatic, vocal, electronic, and chamber music works. He has received commissions from the French Ministry of Culture, the Orchestre philharmonique de Radio-France, the Südwestfunk Baden-Baden, IRCAM, the Percussions de Strasbourg, the Ensemble Intercontemporain, Court-Circuit, 2e2m, the Ensemble Orchestral Contemporain, Sillages, INA-GRM, the Nouvel Ensemble Moderne of Montreal, Sixtrum, Ictus, the Festival Musica, BIT 20, the Koussevitsky Foundation, the San Francisco Contemporary Music Players, Athelas, the Orchestre national de Lorraine, the Orchestre philharmonique de Nice, the CIRM, INTEGRA, the Festival Berlioz, and other institutions and organizations in France and abroad.

His works are performed and broadcast in France and beyond, including at festivals such as Donaueschingen, Présences de Radio-France, Agora, the Venice Biennale, the Bath Festial, Festival Musica, the ISCM World Music Days in Stockholm, MNM in Montreal, Musiques en Scènes de Lyon, Manca, Bergen, Ultima in Oslo, and Tage für Neue Musik in Zürich, by groups such as the BBC Symphony Orchestra, Tonhalle Orchester Zürich, the BBC Scottish Symphony Orchestra, the Philharmonia Orchestra, the Czech Philharmonic, and the Orchestre Philharmonique de Lorraine.

Major collaborations with IRCAM include Voi(rex), which premiered there in 2003 in a performance by Donatienne Michel-Dansac and Ensemble L’Itinéraire, conducted by Pierre-André Valade, and Apocalypsis, which premiered in 2006 at the Maison de Radio France in another performance by Donatienne Michel-Dansac, Valérie Philippin and BIT20 during the Festival Agora. Apocalypsis was awarded the Prix Francis et Mica Salabert in 2007. In 2022, his first opera, L’annonce faite à Marie, based on the text by Paul Claudel, was premiered at Nantes Opera House.

Leroux has received many awards and honors, including the Prix Hervé Dugardin, the 1996 award for best premiere of the year for (d’)Aller, the SACEM Composers Prize, the Prix André Caplet et Nadia et Lili Boulanger of the Académie des Beaux-Arts of the Institut de France, and the Arthur Honegger Prize of the Fondation de France for his entire body of work. In 2015, he was named to the Royal Society of Canada, and the Académie des beaux-arts of the Institut de France awarded him the Fondation Simone et Cino Del Duca Composition Prize. His album Quid sit Musicus was awarded the 2015 Grand Prix du Disque by the Académie Charles Cros.

He has published many articles on contemporary music and given lectures and composition courses at institutions such as the University of California, Berkeley, Harvard University, the Grieg Academy in Bergen, Columbia University, the Royal Conservatory of Copenhagen, the University of Toronto, the Fondation Royaumont, IRCAM, the American Conservatory at Fontainebleau, the Conservatoire de Paris (CNSMDP) and the Conservatoire de Lyon (CNSMDL), Domaine Forget in Québec, and the Georgia Institute of Technology in Atlanta.

From 2001 to 2006, he taught composition for Cursus, IRCAM’s composition and computer music course. In 2005 and 2006, he was the Langlois Foundation visiting professor of music media and technology at McGill University. From 2007 to 2009, he held a residency at the Arsenal de Metz with the Orchestre national de Lorraine, and from 2009 to 2011 was a guest professor at the Université de Montréal (UdeM). Since September 2011, he has taught composition at the Schulich School of Music at McGill University. In 2017, he was a composer in residence for the MEITAR ensemble in Tel-Aviv.