Denbighshire is a county in the north-east of Wales. It borders the Irish Sea to the north, Flintshire to the east, Wrexham to the southeast, Powys to the south, and Gwynedd and Conwy to the west. Rhyl is the largest town, and Ruthin is the administrative centre. Its borders differ from the historic county of the same name.

Until 1974, Denbighshire, or the County of Denbigh, was an administrative county in the north of Wales, later classed as one of the thirteen historic counties of Wales. It was a maritime county, that was bounded to the north by the Irish Sea, to the east by Flintshire, Cheshire and Shropshire, to the south by Montgomeryshire and Merionethshire, and to the west by Caernarfonshire.