The Great Western Railway (GWR) 4700 Class was a class of nine 2-8-0 steam locomotives, designed by George Jackson Churchward. They were introduced in 1919 for heavy mixed-traffic work. Although primarily designed for fast freight, the class also sometimes hauled passenger trains, notably heavy holiday expresses in the summer months. They were unofficially nicknamed "Night Owls" because they were primarily designed to haul goods during the night and they could be seen simmering in the daylight, awaiting their nocturnal duties.

Under the Whyte notation for the classification of steam locomotives, 2-8-0 represents the wheel arrangement of two leading wheels on one axle, usually in a leading truck, eight powered and coupled driving wheels on four axles, and no trailing wheels. In the United States and elsewhere, this wheel arrangement is commonly known as a Consolidation, after the Lehigh and Mahanoy Railroad’s Consolidation, the name of the first 2-8-0.