Sagem was founded in 1925 in Paris by Marcel Môme, Aged 25 he formed the (Society for the General Application of Electricity & Mechanics), a company whose central business would be mechanics. Early products included electrical components, power distribution equipment, cameras, projectors and military equipment.

From 1942, following a request from the French Ministry of Telecommunications, SAGEM developed a new communication system : the telex printer. This date marked their move towards telecommunications.

SAGEM has grouped its activities around two activities:

A Sagem MW3020- A communication branch (SAGEM is ranked second within the French telecommunication equipment providers); - A Defense & Security branch, which covers three domains: Defense (navigation, guided weaponry, military aeronautics), Avionics & Optronics, and Avionics & Piloting (optronics, observation drones, cryptology, biometric systems, secure terminals). The group is ranked third within the French electronic, defense, and security market.