Au gagne petit, Former department store facade on Avenue de l'Opéra, Paris, France

The Gagne-Petit is a historic department store on Avenue de l'Opéra featuring an ornate stone facade with a carved relief of a knife grinder that visually represents the shop's name and purpose. Today it operates as a Monoprix supermarket while its original decorative exterior remains protected as a historical monument.

Bouruet-Aubertot opened a linen shop called Le Gagne-Petit in 1844 at 22 rue des Moineaux, where Ernest Cognacq worked as a salesman. When that street was cut through for the new Avenue de l'Opéra, he built a large store with a luxurious facade at 23 avenue de l'Opéra in 1878. The street facades and roofs were inscribed as monuments historiques on 22 March 1983.

The name "Gagne-Petit" (literally "earns little") referred to the trade of knife grinding, a poorly paid job. The preserved bas-relief over the main door copies a painting by David Teniers the Younger (1610–1690) showing a knife grinder; the sculptor reversed the composition and left it unsigned.

The shop sits directly on Avenue de l'Opéra in a busy commercial area and is easily reached on foot. The protected historical facade is fully visible from the street, making it simple to view the carved details even while passing by.

A dark green marble foundation plaque bears two lines of Roman numerals reading "XXII AOUT / MDCCCLXVII", which gives 22 August 1878, the year the store was built. It sits low on the facade, below the relief of the knife grinder that most passers-by look at first.