It is an announcement that surprised virtually every observer of a search that had been expected to end with a far more prominent name.
The 42-year-old Catalan will take charge on July 1, replacing Kasper Hjulmand, who leaves after just one season following a campaign in which Bayer Leverkusen finished sixth in the Bundesliga — missing Champions League qualification entirely — despite reaching the round of 16 in the competition and the DFB-Pokal semi-finals.
Martínez Novell arrives on a free transfer, his contract at Toulouse having expired at the end of June. Toulouse finished ninth in Ligue 1 in his third and final season in charge, having previously finished eleventh and tenth. His overall record across 120 competitive matches with the French club reads 44 wins, 30 draws and 46 defeats.
Born in Les Franqueses del Vallès, Catalonia, and a former youth goalkeeper, Martínez Novell spent the early part of his coaching career working with Barcelona's and Espanyol's academy structures before taking charge of Kuwait's Under-20 side. Toulouse was his first senior head coach position in professional football.
Leverkusen sporting director Simon Rolfes defended the appointment with conviction.
"Carles Martínez has successfully developed numerous young players at Toulouse and formed an internationally shaped squad into a cohesive unit. He brings valuable experience from his time in FC Barcelona's youth academy to Leverkusen.
"Carles is a coach with clear principles and a modern footballing concept. We are convinced he can set the right impulses for our sporting future."
Club chief executive Fernando Carro added: "We are convinced that Carles Martínez with his convincing profile as a coach fits very well with our standards. He embodies a modern type of coach who can develop our highly talented squad, raise it to a consistently high level and lead it to measurable success."
Martínez favours a 3-4-3 system built on technical passing combinations and defensive organisation — a structure considered well-suited to Leverkusen's existing squad profile. His formal presentation at the BayArena takes place on Friday at noon.