Cerdanya or often La Cerdanya, is a natural comarca and historical region of the eastern Pyrenees divided between France and Spain. Historically it was one of the counties of Catalonia.
Cerdanya has a land area of 1,086 km², divided almost evenly between Spain and France. In 2001 its population was approximately 26,500, of whom 53% lived on Spanish territory. Its population density is 24 residents per km². The only urban area in Cerdanya is the cross-border urban area of Puigcerdà-Bourg-Madame, which contained 10,900 inhabitants in 2001.
The area enjoys a high annual amount of sunshine – around 3,000 hours per year. For this reason, pioneering large-scale solar power projects have been built in several locations in French Cerdagne, including Font-Romeu-Odeillo-Via, the Themis plant near Targassonne, and Mont-Louis Solar Furnace in Mont-Louis.