Merseyside Police is the territorial police force responsible for policing Merseyside in North West England. The service area is 647 square kilometres with a population of around 1.5 million. As of September 2017 the service has 3,484 police officers, 1,619 police staff, 253 police community support officers, 155 designated officers and 208 special constables. The force is led by Chief Constable Serena Kennedy.

Merseyside is a ceremonial and metropolitan county in North West England. It borders Lancashire to the north, Greater Manchester to the east, Cheshire to the south, the Welsh county of Flintshire across the Dee Estuary to the southwest, and the Irish Sea to the west. The largest settlement is the city of Liverpool.