Compagnie des Montres Longines Francillon S.A. or Longines is a Swiss luxury watch brand based in Saint-Imier, Switzerland. It was founded by Auguste Agassiz in 1832 with two other friends, Henri Raiguel and Florian Morel under the name Raiguel Jeune & Cie. By 1846, however, Agassiz's partners retired from the business leaving him the sole owner of the company.

Several years later, his nephew Ernest Francillon joined the business and pushed it to new heights by pioneering innovations and distinguishing the brand from its competitors. One of which is the production of crown-wound pocket watches rather than the key-wound alternative prevalent during the time. With him at the helm, the company moved towards more modern production methods and into mass production. After establishing their first factory by 1867, they produced Longine's first in-house movement - the 20A and won the 1867 Universal Exhibition in Paris.

In 1878, Longines developed its first chronograph movement, the 20H - a mono-pusher chronograph eventually entering into the production of stopwatches suitable for precise timing in professional events and buildings its reputation in equestrian sports. By 1886, Longines had established itself as a primary supplier of timing equipment for most New York sporting events.

After early issues with counterfeiting, Francillon decided to trademark the name Longines in 1880 and its distinctive winged hourglass logo in 1889, respectively.

From 1927 to 1971, Longines collaborated with companies and personalities such as Weems and Charles Lindberg in producing navigation watches. Notable Longines calibers from this period include Longines 12.68z, Longines 13.33z, Longines 13ZN, Longines 30CH and
Longines 37.9.

In 1983, Longines' owner ASUAG merged with SSIH to form the Société Suisse de Microélectronique et d'Horlogerie (SMH) which eventually became the Swatch Group in 1988.