After discovering the saxophone thanks to François Daneels at the Académie de Musique in Tubize, Michel Mergny attended the Royal Brussels Conservatory, where he obtained Diplômes Supérieurs in Saxophone and Chamber Music. At the same time, he also obtained First Prize in Clarinet at the Royal Mons Conservatory.

He has been a laureate of several competitions, including Pro Civitate and Tenuto. Professor of Saxophone at both the Royal Mons Conservatory and at the IMEP, he has pursued a career as a concert soloist and as a chamber musician and is a founding member of the Quatuor de Saxophones de Dinant. To mark the International Adolphe Sax Year, he recorded a CD entitled Parfums de Sax with the pianist Dominique Duhen. In 1990, he helped to organise the 3rd European Saxophone Days in Dinant; since then he has been an active member of the Music Committee of the International Adolphe Sax Association. Michel Mergny regularly serves on juries in a number of establishments, both in Belgium and abroad, and has served as a member of the jury or of the Arbitration Committee of the various competitions held in Dinant.