Template:Infobox Radio station Classic 21 is a Belgian public FM radio station, part of the RTBF broadcasting organisation. The station, based in Mons, is the only Classic rock radio in Belgium. It plays predominantly Anglophone music of the 1960s to 1990s for a French speaking audience across Wallonia and Brussels and beyond.
Classic 21 was created in 2004, at the same time as "Pure FM", in replacing Radio 21. Marc Ysaye, once best known as the drummer with Machiavel and Burning Plague, has been controller of the station since its creation. Ysaye, great grandson of composer-violinist Eugène Ysaÿe, had become an established feature on Radio 21 with his Sunday morning's Show "Les Classiques du dimanche matin", a show which continues on Classic 21 featuring 60's-80's rock. Another Radio 21 show to have been carried across to Classic 21 is Walter de Paduwa's 'Doctor Boogie' which has been featuring up-beat blues, boogie and zydeco music since 1994 - every show starting with a track by Canned Heat.