Gérard Pesson first studied literature and musicology at the Sorbonne, where he defended a thesis on the Aesthetics of aleatoric music, before entering the classes of Betsy Jolas and Ivo Malec at the Conservatoire National Supérieur de Musique de Paris, where he won two first prizes in the analysis and composition classes. In 1986, he founded the contemporary music review Entretemps. In 1986, he won first prize at the Studium de Toulouse for Les Chants Faëz, and was awarded a prize in the “Opéra autrement” competition for Beau Soir, which was first performed in concert at the Festival d’Avignon in 1989, and then given a stage version at the Festival Musica in Strasbourg in 1990. After winning the Prix de Rome, he was a resident at the Villa Médicis from October 1990 to April 1992. In 1996, Gérard Pesson won the Prince Pierre de Monaco Prize.

Since 1988, Gérard Pesson has devoted himself more particularly to stage music, notably with the choreographer Daniel Dobbels, for whom he creates the original music for his shows. His works have been performed by numerous ensembles and orchestras in France and abroad: Ensemble Fa, Ensemble 2e2m, Ensemble Intercontemporain, Itinéraire, Ensemble Modern, Klangforum Wien, Ensemble Recherche, Ensemble Ictus, Alter Ego, Accroche Note, Erwartung, Orchestre national de Lyon, Orchestre national d’Île-de-France, Symphonieorchester des Bayerischen Rundfunks, etc.

His opera Forever Valley, commissioned by T&M, on a libretto by Marie Redonnet, was premiered in April 2000 at the Théâtre des Amandiers in Nanterre. His opera Pastorale, based on L’Astrée by Honoré d’Urfé, was premiered in Stuttgart in May 2006 in a concert version, then in France, at the Théâtre du Châtelet in 2009 in a stage version. His concerto Future is a faded song was premiered on October 5, 2012 in Zurich with Alexandre Tharaud on piano and the Zurich Orchestra conducted by Pierre-André Valade.

He is also a professor of composition at the Conservatoire national supérieur de musique et de danse de Paris.

He has also been a producer at France Musique since 1986, notably of Boudoirs et autres which ended in July 2014, after 379 broadcasts.