Montbrillant Watch Manufactory was the name given by Breitling to a row of buildings in La Chaux-de-Fonds numbered 1 and 3 Ruelle Montbrillant (formerly 17 and 18 Boulevard de Petit-Château). Breitling based its manufacturing in Montbrillant 3 from 1893 through the 1970s.

Boulevard de Petit-Chãteau was a short road in the hills above La Chaux-de-Fonds connecting the namesake house and grounds to Rue du Haut-des-Combes and the mountain village of la Grebille. Many small watchmakers had located along the quiet Boulevard since the 1850s, and the area was redeveloped and incorporated into the city by 1890. In 1889, La Société d'Embellissement (“the Beautification Society”) purchased a portion of the woods to become a public park in 1891, as new roads and buildings were added to the area.

A new factory was built and by 1893 part of the building was occupied by Léon Breitling, who relocated from Saint-Imier on April 23, 1892. It was a highly visible location, high on a hill with tall gables topped with spears, and was in a fashionable and growing area of town. In 1894, the established La Chaux-de-Fonds firm of Charles Couleru-Meuri relocated to the building, with Breitling's address being number 17 and Couleru-Meuri being number 18. Both companies featured the entire factory building in their advertisements, with Breitling showing a large roof-mounted sign missing in the Couleru-Meuri images.

By 1900, a new road was built behind the factory connecting to Rue du Haut-des-Combes and Rue du Balancier. This was named Ruelle Montbrillant, evoking the name of an 18th century summer palace in Hanover. The street numbers were reversed, reflecting the direction of travel, so the Eastern half (formerly Rue du Petit-Château 18) was now Montbrillant 1 while Breitling's Western half (formerly number 17) was now Montbrillant 3.

Breitling would embrace this new name, referring to the building as Montbrillant Watch Manufactory by 1920 and continuing to use that name for decades to come. Indeed, the official name of the company after Gaston Breitling took over was G.-Léon Breitling S.A. Montbrillant Watch Manufactory. To this day, Breitling uses the Montbrillant name for special and historic models, even though the company vacated the factory after 1969.

This factory remains standing in La Chaux-de-Fonds and is decorated with an original Breitling sign, though it is no longer associated with the horology industry.

The factory was shared between Breitling and many other companies from the very beginning

• Montbrillant 1 (Boulevard du Petit-Château 18 through 1898)
  • Charles Couleru-Meuri (1894-1908)
  • Election (1904)
  • A. Lugrin et Cie. (1906-1907)
  • Rode Watch Co. (1909-1918)
  • Sonex (1919-1924)
  • Darax (1920-1924)
  • Le Stand (1922-1924)
  • Inca SA (1923)
  • Frêne & Juillard (1926-1927)
  • Jules Frêne (1928-1929)
• Montbrillant 3 (Boulevard du Petit-Château 17 through 1898)
  • Léon Breitling (1894-1914)
  • G.-Léon Breitling (1916-1979)
  • Jeanneret-Hüninger & Cie (1899)
  • Lucie Huguenin (1905-1909)
  • I. et J. Meylan (1900-1903)
  • J. Schneider (1900-1903)
  • H. Müller & Fils (1926-1928)

The Eastern building (Boulevard du Petit-Château 18 or Montbrillant 1) was occupied by a series of companies after Couleru-Meuri. Election was founded there in 1904. In 1909, the factory was now listed as the home of Rode Watch Co. This American firm was a mass producer of watches. Rode was replaced in 1919 by Darax and Sonex, with travel clock maker Le Stand joining by 1922. By 1926, the Montbrillant factory was the home instead of component maker Frêne & Juillard, but became a box factory for Henri Stoeckle in 1932. More space in the factory was used by Les Fabriques d'Assortments Réunies, Atelier de Sertissages in 1937, and by 1938 more space was used as a watch factory, now for Roger Béguelin's Rogelin Watch Co. (which relocated to Grenchen a few years later) and Jules Gubler. Zila Watch relied on the facility as a distributor by 1938. It was the home of Henri Jacot from 1950 through 1955. By 1963, it was home again to H. Stoeckle's packaging company.

The Western side was used by Breitling through 1969 but was also used by others Watchmaker James Schneider was located at the same address as Breitling in 1899, Nicely S.A. was there from 1950 through 1953, and it was the home to Brémon SA from 1963 through 1969. Breitling claims that they continued to use the factory through 1979, when Ernest Schneider purchased the firm.