The London and North Eastern Railway (LNER) Thompson Class L1 was a class of 2-6-4T steam locomotives designed by Edward Thompson. The prototype no. 9000 was built in 1945, but the remaining 99 were built under British Railways jurisdiction between 1948–1950. The prototype was well received, however the production batch were not, and all were withdrawn and scrapped between 1960 and 1962.

The London and North Eastern Railway (LNER) was the second largest of the "Big Four" railway companies created by the Railways Act 1921 in Britain. It operated from 1 January 1923 until nationalisation on 1 January 1948. At that time, it was divided into the new British Railways' Eastern Region, North Eastern Region, and partially the Scottish Region.