Montreux (môNtröˈ) [key], resort area (1990 pop. 22,917), on the northeast shore of the Lake of Geneva, Vaud canton, W Switzerland. It is composed of the communes of Le Châtelard, Les Planches, and Veytaux, which were merged in 1962. Montreux is a leading resort on the Lake of Geneva, and lies on a railway line from Geneva and France to Italy. The Montreux Jazz Festival is held there.