The London and South Western Railway L12 class was a class of 20 4-4-0 steam locomotives designed for express passenger work by Dugald Drummond. They were introduced to the London and South Western Railway network in 1904. Despite the class being an unremarkable continuation of the Drummond lineage, one member was involved in the infamous Salisbury rail crash in June 1906. None of the class survived into preservation after their brief career in British Railways ownership.