West Mercia Police, formerly the West Mercia Constabulary, is the territorial police force responsible for policing the counties of Herefordshire, Shropshire and Worcestershire in England. The force area covers 2,868 square miles (7,430 km2) making it the fourth largest police area in England and Wales. The resident population of the area is 1.19 million Its name comes from the ancient kingdom of Mercia.

Herefordshire is a ceremonial county in the West Midlands region of England. It is bordered by Shropshire to the north, Worcestershire to the east, Gloucestershire to the south-east, and the Welsh counties of Monmouthshire and Powys to the west. The city of Hereford is the largest settlement and the county town.