South Yorkshire is a metropolitan county in the Yorkshire and the Humber region of England. It has a population of 1.34 million (2011). It consists of four metropolitan boroughs: Barnsley, Doncaster, Rotherham and 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 west and south-west), West Yorkshire (to the north-west), North Yorkshire (to the north), the East Riding of Yorkshire (to the north-east), Lincolnshire (to the east) and Nottinghamshire (to the south-east). 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. The entirety of South Yorkshire lies within the Sheffield City Region.

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.

South Yorkshire was created from 32 local government districts of the West Riding of Yorkshire (the administrative county and four independent county boroughs), with small areas from Derbyshire and Nottinghamshire.