Sir William Stanier's London, Midland and Scottish Railway (LMS) Class 4P 2-Cylinder 2-6-4T was a class of 206 steam locomotive built between 1935 and 1943.

No 2429 had a starring role as Celia Johnson's branch line engine in the 1945 film Brief Encounter, which was made at Carnforth station during the winter of 1944–45.

None have been preserved (though the original of the 3-Cylinder 2-6-4T version, number 2500, is preserved at the National Railway Museum, and two examples of the nearly identical LMS Fairburn 2-6-4T are also still in existence).

This model has been reproduced in O gauge by ACE Trains in 2009; both LMS and BR black versions have been manufactured.

This article relating to steam locomotives operated in the United Kingdom is a stub.