Atelier de Mrfcanique et d’Automobiles Grousset et Fils was a French automobile manufacturer based in Firminy, Loire. Founded by Paul Grousset and his sons, the company operated between 1904 and 1905. Initially, the Grousset family ran a general engineering business, which allowed them to venture into automobile production.

During its brief existence, the company produced approximately twelve cars for local clients. However, after this short foray into the automotive industry, Grousset et Fils shifted its focus to the manufacture of hexagonal screws. This pivot marked a return to their core engineering roots, and the firm continued to operate in this capacity, which remains its primary business to this day.