The British Rail Class 57 is a type of diesel locomotive that was remanufactured from Class 47s by Brush Traction of Loughborough between 1998 and 2004 and was produced in response to an order placed in November 1997 by the recently privatised freight operator Freightliner.

The company sought to have its aging Class 47s, some of which had become increasingly unreliable and uncompetitive in comparison to new-build counterparts. Accordingly, redundant locomotives were handed over to Brush, where they were fitted with re-conditioned Electro-Motive Diesel (EMD) engines and the same model of traction alternator as that fitted to the Class 56 heavy freight locomotive.

As a result of this scheme, improved reliability and performance was recorded; Freightliner placed multiple follow-on orders for more to be rebuilt, as would other operators. However, Freightliner abandoned its long-term plans to acquire twenty-five Class 57s in favour of new-built Class 66 locomotives instead.