The Stadler Eurolight is the brand name for a family of 4-axle Bo'Bo' mainline diesel-electric locomotives with sub-20-tonne axleloads for passenger and freight trains produced by Stadler Rail.

Stadler Rail is a Swiss manufacturer of railway rolling stock, with an original emphasis on regional train multiple units and trams, but moving also into underground, high speed, intercity and sleeper trains. It is also producing niche products, such as being one of the last European manufacturers of rack railway rolling stock. Stadler Rail is headquartered at its place of origin in Bussnang, Switzerland. Stadler Rail employed 13,400 employees by 2022.