The Vale of Glamorgan (Welsh: Dyffryn (or Bro) Morgannwg) is an exceptionally rich agricultural area in the southern part of Glamorgan, Wales. It has a rugged coastline, but its rolling countryside is quite untypical of Wales as a whole.

The Vale also boasts many tourist attractions which lure many visitors every year, these include Barry Island Pleasure Park, Vale of Glamorgan Railway, St Donats Castle, Cosmeston Country Park and many more.

It has been a county borough since 1996, previously being part of South Glamorgan. It is also a parliamentary constituency, with John Smith as its Member of Parliament. The main town and largest centre of population is Barry. Other small towns are Cowbridge, Dinas Powys, Llantwit Major and Penarth, but a large proportion of the population inhabits villages, hamlets and individual farms.

The awesome yellow-grey cliffs on the Glamorgan Heritage Coast (which stretches between Llantwit Major to Ogmore by Sea) are absolutely unique on the Celtic seaboard (i.e Cornwall, Wales, Ireland and Brittany) as they are formed of liassic limestone - totally unqiue for a Celtic nation. They were formed 200 million years ago when Wales (as well as Cornwall and Ireland) lay underneath a warm, shallow, equatorial sea during the beginning of the jurassic age. Today the cliffs contain elements of jurassic age sea-creatures (although not land dinosaurs - the Celtic nations were all underneath the sea), such as amonites. The stratification of overlapping shale and limestone was caused by a geological upheaval known as the Amorican oragany, which literally pushed the cliffs out of the sea, contorting them as they did so. (This stratification can also be found on other parts of the Celtic seaboard, such as Bude in Cornwall, across the Bristol Channel). As the cliffs and land contain elements of calcium carbonate found in the limestone, it allows farmers in the vale to grow crops which would be difficult elsewhere in Wales or the west country, such as Cornwall (whose soil is predominantly acidic). The liassic limestone is also used in the vale for building materials; in previous centuries it was taken by sloops across the Bristol Channel to north Cornish ports such as Bude, Boscastle and Port Issac to fertilise Cornwall's poor slate soils for the farming communities.

The district borders Cardiff, Rhondda Cynon Taff and Bridgend to the north, and the Bristol Channel to the south.