Simone, who played in attack for Milan and Monaco during his career, will be assisted by Jean Petit, the French club have confirmed.
Monaco are struggling domestically following their relegation from the top flight last term. They are currently second from bottom in the standings.
Simone is 42 and also has a past with French giants Paris Saint-Germain as a player. Despite a decent career at club level, he only won four caps for his country.