British Railways (BR), which from 1965 traded as British Rail, was a state-owned company that operated most rail transport in Great Britain from 1948 to 1997. Originally a trading brand of the Railway Executive of the British Transport Commission, it became an independent statutory corporation in January 1963, when it was formally renamed the British Railways Board.

The railway system in Great Britain is the oldest railway system in the world. The first locomotive-hauled public railway opened in 1825, which was followed by an era of rapid expansion. Most of the track is managed by Network Rail, which in 2017 had a network of 9,824 miles (15,811 km) of standard-gauge lines, of which 3,339 miles (5,374 km) were electrified. In addition, some cities have separate metro, light rail and tram systems, among them the historic London Underground and the Glasgow Subway. There are also many private railways, some of them narrow-gauge, which are primarily short lines for tourists. The main rail network is connected with that of continental Europe by the Channel Tunnel and High Speed 1, opened in 1994 and 2007 respectively.