The British Rail Class 117 diesel multiple units (DMUs) were built by Pressed Steel from 1959 to 1961. It was a licence-built variant of the British Rail Class 116.
A total of 123 Class 117's were built by Pressed Steel between 1959 and 1961. The Class 116 was ordered in large numbers which Derby Works could not fulfil, so the work was sub contracted. When first introduced in 1960, these three-car units were all based with the similar Class 121 single carriage (railcar) units on British Railways Western Region for suburban work out of London Paddington. The units were largely based at Reading and Southall depots. The units remained here for many years working these services.