Mk 1

British Railways Mark 1 is the family designation for the first standardised designs of railway carriages built by British Railways (BR) from 1951 until 1974, now used only for charter services on the main lines or on preserved railways.

The Mark 1 coaches were built in two distinct tranches: the early vehicles (1951–1960) and the 'Commonwealth' stock (named from the type of bogie used) from 1961 onwards.