Mid Wales is the name given to the area of Wales lying between North and South Wales. It borders England via the Welsh Marches to the east and the Irish Sea via Cardigan Bay to the west (West Wales is to the south-west). The region approximately consists of the modern counties of Ceredigion and Powys, or the pre-1974 counties of Brecknockshire, Cardiganshire, Montgomeryshire and Radnorshire. Mid Wales is also sometimes said to include Merioneth, but this is far from usual.

Mid Wales is dominated by the remote Cambrian Mountains which run down the centre of the area including the area sometimes referred to as the "Desert of Wales". It is sparsely populated, with most settlements being situated to the east of the mountains, including Builth Wells, Welshpool, and Newtown. There are also a few towns on the coast, most notably Aberystwyth, the de facto capital of the region.