Greasby is a large village on the Wirral Peninsula, Merseyside, England. A predominantly residential area, it is contiguous with Upton to the east and Saughall Massie to the north. The small village of Frankby is to the immediate west. Historically within the county of Cheshire, it is part of the Greasby, Frankby and Irby Ward of the Metropolitan Borough of Wirral and is in the parliamentary constituency of Wirral West.

The Wirral Peninsula, known locally as the Wirral, is a peninsula in North West England. The roughly rectangular peninsula is about 15 miles (24 km) long and 7 miles (11 km) wide, and is bounded by the Dee Estuary to the west, the Mersey Estuary to the east, and Liverpool Bay to the north.