The French Prealps (French: Préalpes françaises [pʁealp fʁɑ̃sɛːz]) are a group of subalpine mountain ranges of medium elevation located immediately west of the French Alps. They roughly stretch from Lake Geneva southwest to the rivers Isère and Drôme; east to a line running from Chamonix, to Albertville, to Grenoble, to Gap, to Barcelonette; and south from Grasse to Vence.
In the northern subalpine regions, the various ranges are easily identifiable by geographical separations, such as the Voreppe Gorge between Vercors and Chartreuse, or Chambéry, which sits in a valley between the Bauges and Chartreuse ranges. In the southern subalpine regions, the ranges are generally disorganized and lack the wide, deep valleys that divide them in the north.