The London, Brighton and South Coast Railway (LB&SCR) H1 class was a class of 4-4-2 steam locomotives for express passenger work. They were designed by D. E. Marsh and were built by Messrs Kitson and Company in 1905 and 1906.

Under the Whyte notation for the classification of steam locomotives by wheel arrangement, 4-4-2 represents a configuration of a four-wheeled leading bogie, four powered and coupled driving wheels, and two trailing wheels supporting part of the weight of the boiler and firebox. This allows a larger firebox and boiler than the 4-4-0 configuration.