Derby (dar-bi) is a former vintage era automobile maker based in Courbevoie, Seine, France. Derby was founded in Courbevoie by Bertrand Montet in 1921 to build voiturettes (cyclecars). These were powered by American vee-twin motorcycle engines, which were shortly replaced with Chapuis-Dorniers. In this form, it became a close copy of Citroen's 5CV ("five horsepower").