The SECR N class was a type of 2-6-0 steam locomotive designed in 1914 by Richard Maunsell for mixed-traffic duties on the SECR. Built between 1917 and 1934, it was the first non-GWR type to use and improve upon the basic design principles established by GWR Chief Mechanical Engineer George Jackson Churchward. The N class was based on the GWR 4300 Class design, improved with Midland Railway concepts.

The N class was mechanically similar to the SECR K class 2-6-4 passenger tank engine, also by Maunsell. It influenced future 2-6-0 development in Britain and provided the basis for the 3-cylinder N1 class of 1922. The class replaced obsolete 0-6-0s as part of the SECR's fleet standardisation, as they used parts interchangeable with those of other classes.

80 N class locomotives were built in three batches between the First and Second World Wars. 50 were assembled from kits of parts made at the Royal Arsenal, Woolwich, giving rise to the nickname of "Woolworths". They worked over most of the Southern network and the last was withdrawn in 1966. One N class locomotive has been preserved.