Saint Galmier is a spa town and the source of Badoit mineral water. The thermal spring was known of in Gallo-Roman times, but its fame increased with the general growth in interest in thermal cures in Europe during the nineteenth century.

Before Auguste Badoit appeared on the scene and commercialised the water in the 1830s, both the water, and the spring from which it emerged, were known as "Fontfort". It is for this reason that briefly, during the French Revolutionary period, the town was known as "Fontfortville".