This is a list of railway lines in Great Britain that are currently in operation, split by country and region. There are a limited number of main inter-regional lines, with all but one entering Greater London. The line from London to the Channel Tunnel is the only line designated 'high speed', although the other main routes also operate limited-stop express services. The bulk of the secondary network is concentrated in London and the surrounding East and South East regions; an area marketed by National Rail as London and the South East. The majority of these lines are radial to London. There is a further concentration of routes around Birmingham in the West Midlands and in the urbanised part of northern England that stretches from Liverpool in the west, via Greater Manchester to Leeds in the east. Some areas, such as Wales and Scotland, have relatively sparse railway provision. There are local lines throughout all areas of Great Britain with some services designated as community railways.

England

London

This is a list of routes entirely contained within Greater London.

Terminus

South East England

This is a list of all routes that enter the South East England region.

South West

This is a list of all routes that enter the South West England region.

Terminus

North West England

This is a list of all routes that enter the North West England region.

West Midlands

This is a list of all routes that enter the West Midlands region.

East of England

Anglia

This is a list of all routes that enter the East of England region.

East Midlands

This is a list of all routes that enter the East Midlands region.

North Eastern

This is a list of all routes that enter the Yorkshire and the Humber and North East England region.

Scotland

Scotrail Intercity lines

Glasgow commuter lines

Edinburgh commuter lines

Rural lines and Great Scenic Railways

Wales

Main lines

Cardiff commuter lines

Rural lines

Lines under construction