Mathias Malzieu is the lead singer of the French band Dionysos, which he co-founded in 1993 when he lived in Valence in Drôme (Auvergne-Rhône-Alpes). Three of his schoolfriends, Eric Serra Tosio, Michael Ponton, and Guillaume Garidel, were among the band's original members. Malzieu is a prominent figure in French rock with Dionysos, for which he writes, composes, and performs the songs. Unwilling to choose between his vocation as a singer and that of an author, he naturally decided to blend the two.

After a collection of short stories, 38 mini westerns, and a novel, Maintenant qu'il fait tout le temps nuit sur toi, he achieved widespread popular success with La Mécanique du cœur (2007), translated into 20 countries, and the autobiographical account, Journal d’un vampire en pyjama (2016), which won the Prix Essai France Télévisions and the Grand Prix des Lectrices de Elle.