The LMS Ivatt Class 4 2-6-0 is a class of steam locomotive primarily designed for medium freight work but also widely used on secondary passenger services. The London, Midland and Scottish Railway (LMS) ordered 162 of this type between 1947 and 1952, but only three were built by the LMS before nationalisation in 1948. Designed by George Ivatt, they were classified 4F by the LMS and 4MT by British Railways (BR).

Henry George Ivatt, known as George Ivatt, was the post-war Chief Mechanical Engineer of the London Midland and Scottish Railway. He was the son of the Great Northern Railway locomotive engineer Henry Ivatt. George Ivatt was born in Dublin, Ireland, and educated at Uppingham School, England. He married Dorothy Sarah Harrison (1881-1962) in 1913.