The British Rail Class 104 diesel multiple units were built by Birmingham Railway Carriage and Wagon Company from 1957 to 1959.  A product of British Rail's Modernisation Plan of 1954, the 104s were designed for general branch line and commuter routes.

The first units ordered were for the London Midland Region, with the majority of the class for use in North West of England. The Class 110 was a re-engineered version of the 104 with more powerful engines, but did not last as long in service. The 104s had asbestos insulation removed during the 1970s.