Francis Vallès studied history and geography before he began his studies in fine arts in Saint-Étienne. In 1983, he published his first comic, 'Une Enquête à chaud qui jette un froid' in Triolo magazine, and he began a collaboration with Je Bouquine, for which he made comic adaptations of novels like 'The Three Musketeers' and 'Oliver Twist'. Magic Strip published two books of his comic series 'Simon Francoeur' in 1983 and 1986.
In 1989, he created 'Jean-Louis Étienne, le Marcheur du Pôle' with Richez and J.-L. Étienne, and started his series 'Dorian Dombre' with José-Louis Bocquet at Glénat. Between 1992 and 1999, Vallès worked with scenario writer Jean van Hamme on the masterpiece 'Les Maîtres de l'Orge', a 8 volume saga about the Steenfort dynasty of beer brewers.
Vallès has cooperated with Stephen Desberg on series like 'Tosca' (Glénat, 2001-05) and 'Rafales' (Le Lombard, 2005-08). Since 2009 he works with Van Hamme and Alcante on the historical series 'Rani' for Le Lombard.