The London and North Eastern Railway (LNER) Class B17, also known as "Sandringham" or "Footballer" class was a class of 4-6-0 steam locomotive designed by Nigel Gresley for hauling passenger services on the Great Eastern Main Line. In total 73 were built.

Sir Herbert Nigel Gresley was a British railway engineer. He was one of Britain's most famous steam locomotive engineers, who rose to become Chief Mechanical Engineer (CME) of the London and North Eastern Railway (LNER). He was the designer of some of the most famous steam locomotives in Britain, including the LNER Class A1 and LNER Class A4 4-6-2 Pacific engines. An A1 Pacific, Flying Scotsman, was the first steam locomotive officially recorded over 100 mph in passenger service, and an A4, number 4468 Mallard, still holds the record for being the fastest steam locomotive in the world (126 mph).