No. 4472 Flying Scotsman is a LNER Class A3 4-6-2 "Pacific" steam locomotive built in 1923 for the London and North Eastern Railway (LNER) at Doncaster Works to a design of Nigel Gresley. It was employed on long-distance express passenger trains on the East Coast Main Line by LNER and its successors, British Railways' Eastern and North Eastern Regions, notably on The Flying Scotsman service between London King's Cross and Edinburgh Waverley after which it was named.

The London and North Eastern Railway Gresley Classes A1 and A3 locomotives represented two distinct stages in the history of the British 4-6-2 "Pacific" steam locomotives designed by Nigel Gresley. They were designed for main line passenger services and later express passenger services, initially on the Great Northern Railway (GNR), a constituent company of the London and North Eastern Railway after the amalgamation of 1923, for which they became a standard design. The change in class designation to A3 reflected the fitting to the same chassis of a higher pressure boiler with a greater superheating surface and a small reduction in cylinder diameter, leading to an increase in locomotive weight. Eventually all of the A1 locomotives were rebuilt, most to A3 specifications, but no. 4470 was completely rebuilt as Class A1/1.