Fortis was founded by Walter Vogt in 1912. Twelve years after its establishment, Vogt set up production with John Harwood, inventor of the automatic wristwatch. In 1926, Fortis released the patented Harwood Automatic, the first self-winding wristwatch, at Baselword. In 1937, Fortis commemorated the company's 25th anniversary by manufacturing and marketing its first chronographs, including the Rolls and the Autorist. The Autorist was also designed by John Harwood and used the movement of the strap to power the watch. By 1943 Fortis introduced the world's first waterproof watches with the Fortissimo models, which were increasingly popular.

In 1962 the Spacematic automatic was constructed to hold up in extreme conditions and temperature changes. The watch was tested by the seven members of a US space mission. In 1994 Fortis introduced strict endurance tests. This same year the Star City Training Center chose the Fortis Official Cosmonauts Chronograph as part of its issued equipment. Fortis automatic wristwatches have proven their space capability inside and outside of the protection of the space station. Since 1994 Fortis has been the exclusive supplier of manned space missions authorized by the Russian Federal Space Agency.