The River Don (also called Dun in some stretches) is a river in South Yorkshire, England. It rises in the Pennines and flows for 70 miles (110 km) eastwards, through the Don Valley, via Penistone, Sheffield, Rotherham, Mexborough, Conisbrough, Doncaster and Stainforth. It originally joined the Trent, but was re-engineered by Vermuyden as the Dutch River in the 1620s, and now joins the River Ouse at Goole in the East Riding of Yorkshire. Don Valley is the local UK parliamentary constituency near the Doncaster stretch of the river.

The Don can be divided into sections by the different types of structures built to restrict its passage. The upper reaches, and those of several of its tributaries, are defined by dams built to provide a public water supply. The middle section contains many weirs, which were built to supply mills, foundries and cutlers' wheels with water power, while the lower section contains weirs and locks, designed to maintain water levels for navigation. The Don's major tributaries are the Loxley, the Rivelin, the Sheaf, the Rother and the Dearne.

South Yorkshire is a metropolitan county in the Yorkshire and the Humber region of England. It has a population of 1.29 million. It consists of four metropolitan boroughs: Barnsley, Doncaster, Rotherham, and City of Sheffield. South Yorkshire was created on 1 April 1974 as a result of the Local Government Act 1972.

Lying on the east side of the Pennines, South Yorkshire is landlocked, and borders Derbyshire (to the south-west), West Yorkshire (to the northwest), North Yorkshire (to the north), the East Riding of Yorkshire (to the northeast), Lincolnshire (to the east) and Nottinghamshire (to the southeast). The Sheffield Urban Area is the ninth most populous conurbation in the UK, and dominates the western half of South Yorkshire with over half of the county's population living within it.

South Yorkshire County Council was abolished in 1986, and so its districts (the metropolitan boroughs) are now effectively unitary authority areas; however, the metropolitan county, which is some 1,552 square kilometres (599 sq mi), continues to exist in law and as a geographic frame of reference. As a ceremonial county, South Yorkshire has a Lord Lieutenant and a High Sheriff.

Yorkshire (/ˈjɔːkʃə/) is a historic county of Northern England and the largest in the United Kingdom. Due to its great size in comparison to other English counties, functions have been increasingly undertaken over time by its subdivisions, which have also been subject to periodic reform. Throughout these changes, Yorkshire has continued to be recognised as a geographical territory and cultural region. The name is familiar and well understood across the United Kingdom and is in common use in the media and the military, and also features in the titles of current areas of civil administration, such as North Yorkshire, South Yorkshire, West Yorkshire and East Riding of Yorkshire. The county's name is commonly abbreviated as Yorks.

Within the borders of the historic county of Yorkshire are areas which are widely considered to be among the greenest in England, due to the vast stretches of unspoiled countryside in the Yorkshire Dales and North York Moors and to the open aspect of some of the major cities. Yorkshire has sometimes been nicknamed God's Own County. The emblem of Yorkshire is the white rose of the English royal House of York, and the most commonly used flag representative of Yorkshire is the White Rose on a dark blue background, which after years of use, was recognised by the Flag Institute on 29 July 2008.Yorkshire Day, held on 1 August, is a celebration of the general culture of Yorkshire, ranging from its history to its own dialect.

Don River or River Don may refer to: