Decazeville (Occitan: La Sala) is a commune in the Aveyron department in the Midi-Pyrénées region in southern France.
The commune was created in the 19th century because of the Industrial Revolution and was named after the Duke of Decazes (1780–1860), the founder of the factory that created the town.
The town is built on coal. La Salle (the former name) produced coal since the 16th century. It was exported in small quantities to Bordeaux.
Louis XIV and his successors gave mines to their mistresses. The Duke of Decazes inherited such mines, and in 1826 he created, with the help of a technician named Cabrol, the "Houillères et Fonderies de l'Aveyron" (Mines and Foundries of Aveyron) which were to make this small village into a center of ironworking.
Under Napoléon III, the city took the name of Decazeville, and a statue of Decazes dressed in a Roman toga was erected.
The high point of iron production was reached early in the 20th century, with 9000 employees and 1 million tons of steel produced. The production then decreased, and the town has since diversified its industry: metallurgy, woodworking, metal fabrication, and production of steel tubing.