Born in Ixelles Christian Denayer grew up in post-war Belgium. Because of his passion for cars, he became Jean Graton's assistant when he was 17 years old. He cooperated on about 10 albums of Graton's Formula 1 series 'Michel Vaillant'. In addition, he made gag pages for Junior, short stories for Tintin with Yves Duval, as well as 'Alain Bercy' in Formule 1 (1967) and 'L'Écurie Europe' in J2 Jeunes. He later worked as the assistant of Tibet on 'Ric Hochet'. Tibet encouraged him to create a comic of his own, which resulted in 'Yalek', a comic series scripted by André-Paul Duchâteau and published in Le Soir Jeunesse from 1969.
For the same paper and with the same writer, he then produced 'Alain Chevallier', which gave him another chance to draw racing cars. A year earlier, Denayer and Duchâteau had already launched 'Les casseurs'.
By 1989 he was hired by publisher Claude Lefrancq to draw 'T.N.T.',. He also remained active for Lombard, producing both script and artwork for five books of the teen comic 'High School Generation' between 1994 and 1998. In 2000, he started working with Jean Van Hamme on the hit detective series 'Wayne Shelton', published by Dargaud. After two episodes, Van Hamme was succeeded by Thierry Cailleteau, but he returned as the series writer in 2010.