After publishing the short stories 'Belles Histoires de l'Oncle Paul' in the magazine Spirou between 1963 and 1966, Claude Renard attended the Sint-Lukas Institute in Brussels, where he studied painting. He took a few courses in comic art by Eddy Paape, and became his assistant until 1976. For eight years, he ran the famous Atelier R., where he educated a great number of famous Belgian comic artists, including Andréas, Benoît Sokal, Philippe Foerster, Antonio Cossu, Yves Swolfs and Philippe Berthet. Every year, he edited 'Le Neuvième Rêve', listing his students's work.

In 1980, with François Schuiten, he created 'Aux Médianes de Cymbiola', and 'Le Rail' a year later. They also did the art direction and costume design for the movie 'Gwendoline' by director Just Jaeckin in 1984. In 1983, he created the series 'Ivan Casablanca' for the magazine Métal Hurlant. In collaboration with Yves Vasseur, he illustrated 'Les Elfes de Pomariolus' in 1986 and 'Moneuse' in 1987. An accomplished comic artist, Renard is even more famous for the work he has done in the educational field.