The SECR H Class is a class of 0-4-4T steam locomotive originally designed for suburban passenger work, designed by Harry Wainwright in 1904. Most of the sixty-six members of the class were later equipped for push-pull working for use on rural branch lines.
The H class boiler design was found to be so successful that it was later used as a standard replacement boiler on the SECR R1 class, LCDR B1 class, LCDR B2 class, LCDR R class, SER O1 class, SECR Q1 class, and SER R1 class. The majority of the class replaced Q class locomotives on the London suburban services of the SER and remained on these duties until after they entered Southern Railway stock in 1923.
Two members of the class were withdrawn during the Second World War, but the remaining 64 entered British Railways stock in 1948. 45 of the survivors were equipped for push-pull train working between 1949 and 1960, and the class was increasingly used on motor-trains on rural branches. One has been preserved.