Dudley Castle is a ruined fortification in the town of Dudley, West Midlands, England. Dudley Zoo is located in its grounds. The location, Castle Hill, is an outcrop of Wenlock Group limestone that was extensively quarried during the Industrial Revolution, and which now along with Wren's Nest Hill is a Scheduled Ancient Monument as the best surviving remains of the limestone industry in Dudley. It is also a Grade I listed building. The Dudley Tunnel runs beneath Castle Hill, but not the castle itself.
In 1889, the extra-parochial place of Dudley Castle, formerly in Worcestershire, became a detached part of Staffordshire, surrounded by the county borough of Dudley, itself a detached part of Worcestershire. In 1894, [on the establishment of rural districts], the area became the only parish in Dudley Rural District. In 1929, it was absorbed by the civil parish and county borough of Dudley.
Dudley Castle Hill was also considered to be part of Dudley Rural District.