Frenchelon is the nickname given to French signal intelligence system in reference to its anglo-saxon counterpart ECHELON. Its existence has never been officially acknowledged by French authorities, although numerous journalists, based on military informations have mentioned it, since the European Union investigated ECHELON and also its implications in counter-terrorism.

The system is alledgedly operated by DGSE, whose Direction Technique (Technical Direction) is responsible for signal intelligence. The most important station is in Domme near Sarlat in Perigord, other stations on French metropolitan territory are (Alluets-Feucherolles, Mutzig, Mont Valérien, Plateau d'Albion, St Laurent de la Salenque, Cap d’Agde, Solenzara, Filley), there are some other stations in overseas territories and former colonies (Saint-Barthélemy,Bouar,Djibouti,Mayotte,Reunion,Kourou and Tontouta in New Caledonia).

These stations in addition to the DGSE headquarter boulevard Mortier in Paris intercept electronic communications, decipher using software coded communications of diplomatic, military or industrial origin.

It shouldn't be confused with the French Army's official listening system Emeraude, which used to be mistakenly conflated with Frenchelon.