The Great Western Main Line at Dawlish

The Great Western Main Line crosses the River Thames on Maidenhead Railway Bridge

The Great Western Main Line is a main line railway in the United Kingdom, corresponding to the principal routes of the pre-1948 Great Western Railway which were subsequently taken over by the Western Region of British Railways and are now operated by First Great Western.

The original Great Western Main Line runs from London Paddington via Reading, Swindon, Bath, Bristol Temple Meads and Exeter to Plymouth.

The route that diverges at Swindon to Bristol Parkway, the Severn Tunnel, Cardiff and Swansea is also part of the Great Western Main Line, as is the route that diverges at Reading to reach Exeter more directly via Newbury, Westbury and Castle Cary.