Proteus Airlines was a French regional airline with its head offices in Saint-Apollinaire, Côte-d'Or, France, near Dijon, and in Saint-Étienne. Founded in 1986, it remained operational until 2001. The airline was originally known as Proteus Air System. In May 1996, it began scheduled services under its new name. In August 1997, the airline signed a franchise agreement with Air France. In October 1999 Proteus acquired another regional airline, Flandre Air. On 30 March 2001, Proteus, Flandre, and Regional Airlines merged into Régional Compagnie Aérienne Européenne.