The Great Western Railway (GWR) 4900 Class or Hall Class is a class of 4-6-0 mixed traffic steam locomotives designed by Charles Collett. A total of 259 were built, numbered 4900–4999, 5900–5999 and 6900–6958. The LMS Stanier Class 5 4-6-0 and LNER Thompson Class B1 both drew heavily on design features of the Hall Class. After nationalisation in 1948, British Railways gave them the power classification 5MT.