Deeside is the name given to a predominantly industrial conurbation of towns and villages in Flintshire and Cheshire on the Wales–England border lying near the canalised stretch of the River Dee that flows from neighbouring Chester into the Dee Estuary. These include Connah's Quay, Shotton, Queensferry, Aston, Garden City, Sealand, Broughton, Bretton, Hawarden, Ewloe, Mancot, Pentre, Saltney and Sandycroft. The population is around 50,000, with a plurality (17,500) living in Connah's Quay.

Flintshire is a county in the north-east of Wales. It has a maritime border with Merseyside along the Dee Estuary to the north, and land borders with Cheshire to the east, Wrexham County Borough to the south, and Denbighshire to the west. Connah's Quay is the largest town, while Flintshire County Council is based in Mold.