The Drewry Car Co was a railway locomotive and railcar sales organisation for most of its life. Only at the start and the end of its life did it build its own products, relying on sub-contractors for the rest of its time. It was quite separate from the lorry-builder, Shelvoke and Drewry, but it is believed that James Sidney Drewry was involved with both companies.

Drewry & Sons ran a motor and cycle repair business in Herne Hill, London, and started building BSA engined inspection railcars. A ready market was found in South America, Africa, and India. Drewry Car Co Ltd was registered on 27 November 1906. In 1908 BSA (of motor-cycle fame) took over building the railcars in Small Heath, Birmingham. In 1911 building was taken over by Baguley Cars, Burton-on-Trent. From 1930 a lot of Drewry locomotives were built by English Electric companies