The London Midland and Scottish Railway Fowler Class 4F is a class of 0-6-0 steam locomotive designed for medium freight work. They represent the ultimate development of Midland Railway's six coupled tender engines.

The 4F was based on the 197-strong Midland Railway 3835 Class of 1911, with only a few modifications, primarily the adoption of left-hand drive instead of right-hand drive. They originally had been designed by Henry Fowler, who from 1925 became CME of the LMS. Midland Railway locomotives were notorious for their short axle-box bearings, which were prone to overheating. This design feature was perpetuated in the LMS 4F. The problem was eventually solved with the fitting of mechanical lubricators.

The LMS constructed 530 of the locomotives between 1923 and 1928, numbered sequentially from where the Midland engines left off from 4027. A further 45 examples were reluctantly authorised by William Stanier in 1937 at the behest of the operating department.

All entered British Railways stock in 1948. BR added 40000 to their numbers. They were all withdrawn between 1959 and 1966. Three LMS-built 4Fs survive, with the first-built LMS 4F, No. (4)4027, being part of the National Collection. In addition, one Midland 4F, No. (4)3924 has also survived.