The British Rail Class 502 was a type of electric multiple-unit passenger train, originally built by the London, Midland and Scottish Railway at its Derby Works. Introduced in 1940 and withdrawn by 1980, they spent the whole of their working lives on the electrified railway lines north of Liverpool.

The trains were designed to replace older electric trains built by the Lancashire and Yorkshire Railway on the lines from Liverpool Exchange railway station to Southport and Ormskirk. These lines were electrified with a direct current (DC) third rail. The Class 502s entered service between 1940 and 1943. They were DC-only and operated as both three-car and two-car sets, which could be coupled together to form five-car or six-car sets for use on the busier services.

A two-car set (driving motor 28361 and driving trailer 29896) was claimed for preservation by the National Railway Museum. In March 2012 the unit was moved to the base of the Merseyside Transport Trust in Burscough, Lancashire.