The GWR 5700 Class, or 57xx class, is a class of 0-6-0 pannier tank steam locomotive, built by the Great Western Railway (GWR) and British Railways (BR) between 1929 and 1950. With 863 built, they were the most prolific class of the GWR, and one of the most numerous classes of British steam locomotive. Although officially designated by GWR as "light goods and shunting engines", they were also used for passenger working on branch, suburban, and shorter mainline journeys.