At a young age, Johan de Moor decided to follow in the footsteps of his father, the famous artist Bob de Moor. After his studies in graphic art at the Saint-Luc in Brussels, De Moor began doing polictical caricatures. He started his actual comics career in a modest way, mostly doing work in the spirit of his father (and subsequently Hergé), and collaborating on the on-going Hergé series, 'Quick et Flupke' from 1981 to 1986.
In 1988, Johan started developing a more personal style. He teamed up with writer Stephen Desberg and created the series 'Gaspard de la Nuit' at Casterman. De Moor began doing more graphic experiments in their next series 'La Vache', that appeared in À Suivre from 1992. In this series, Johan de Moor showcased his graphic abilities with a collage style, combining old clippings of advertisements with African art influences, while playing with the lettering and the coloring. In 1989, he won the Bronzen Adhemar, the official Flemish Community Cultural Prize for Comics.
In 1993, he finished the final episode of 'Cori le Moussaillon' after the death of his father. Two years later, a collection of his press illustrations appeared at Points Image, called 'Je Sais Tout'. In 2001, 'La Vache' was transferred from Casterman to Lombard, and appeared from then on under the name 'Lait Entier'. In 2004, De Moor started the Jungle Book follow up 'Le Dernier Livre de la Jungle' with Desberg and Henri-Joseph Reculé at Lombard. De Moor is also a teacher in comic art at the Saint-Luc Art Institute in Brussels.