Montanier left Real Sociedad for Rennes at the end of last season after leading the Spanish outfit to fourth in La Liga.
"I'm honoured to be given this prize, especially as in La Liga there are some very good coaches," Ligue1.com quotes Montanier as saying. "It's recompense for a season that wasn't easy.
"The main thing is to persevere and keep working. I share this award with my assistant Michel Troin and the rest of the coaching team."
The 48-year-old will be presented with his award in Spain on October 21.