The London and North Eastern Railway (LNER) Thompson Class O1 was a class of 2-8-0 steam locomotive designed by Edward Thompson for freight work.

The first LNER rebuild took place in February 1944, at Gorton Works and a total of 58 locomotives were rebuilt to class O1 in total, with the last being locomotive 63856 in October 1949 during the early British Railways era, after which the programme was halted.

[1] The main modification to the original GCR Robinson Class 8K 2-8-0 design was the incorporation of a standard LNER 100A boiler, Walschaerts valve gear and new cylinders.

[2] The locomotives passed to British Railways (BR) Eastern and North Eastern Regions on 1 January 1948 and were given BR running numbers in the range 63570-63920.

In 2013, Hornby Railways introduced an OO gauge model of the O1 in BR black livery.