Derbi is a manufacturer of motorcycles, scooters, and recreational all-terrain vehicles produced by Nacional Motor S.A.U., a Spanish subsidiary of Piaggio & Co. SpA.

Derbi's origins began with a little bicycle workshop in the village of Mollet near Barcelona, founded in 1922 by Simón Rabasa i Singla. The focus remained the repair and hire of bicycles until May 1944 when Singla formed a limited liability company named Bicicletas Rabasa with the aim of moving into manufacturing bicycles. The venture proved very successful and in 1946, supported by its profits, work began on a motorised version. More moped than motorcycle, this first model, the 48cc SRS included plunger rear suspension, and a motorcycle type gas tank and exhaust system. The SRS proved so successful it prompted a change in the companies direction, and on November 7, 1950, the company changed its name to the Nacional Motor SA. Just prior to this, at that summer's Barcelona Trade Fair, the company unveiled its first real motorcycle, the Derbi 250.