Yorkshire (/ˈjɔːrkʃər, -ʃɪər/ YORK-shər, -⁠sheer) is an area of Northern England which was historically a county and a Kingdom. Despite no longer being used for administration, Yorkshire retains a strong regional identity. The county was named after the city of York.

The south-west of Yorkshire includes the cities of Leeds, Sheffield, Bradford, Doncaster and Wakefield. The north and east of the county includes the southern part of the Teesside conurbation; the port city of Hull is located in the south-east. York is positioned near the centre of the county. Yorkshire has a coastline on the North Sea. The North York Moors occupy the north-east of the county, and the centre contains the Vale of Mowbray and the Vale of York. The west contains part of the Pennines, which includes the Yorkshire Dales.

The county was historically bordered by County Durham to the north, the North Sea to the east, Lincolnshire, Nottinghamshire, Derbyshire, and Cheshire to the south, and Lancashire and Westmorland to the west. It was the largest by area in the United Kingdom. From the Middle Ages the county was subdivided into smaller administrative areas; the city of York was a self-governing county corporate from 1396, and the rest of the county was divided into three ridings – North, East, and West. From 1660 onwards each riding had its own lord-lieutenant, and between 1889 and 1974 the ridings were administrative counties. There was a Sheriff of Yorkshire until 1974. Yorkshire gives its name to four modern ceremonial counties: East Riding of Yorkshire, North Yorkshire, South Yorkshire, and West Yorkshire, which together cover most of the historic county.

Yorkshire Day is observed annually on 1 August and is a celebration of the general culture of Yorkshire, including Yorkshire's history and dialect. Its name is used by several institutions, for example the Royal Yorkshire Regiment of the British Army, in sport, and in the media. The emblem of Yorkshire is a white rose, which was originally the heraldic badge of the Plantagenet royal House of York. The county is sometimes referred to as "God's own country". Yorkshire is represented in sport by Yorkshire County Cricket Club and Yorkshire Rugby Football Union.

There are several ways of defining Yorkshire, including the historic county and the group of four modern ceremonial counties. The county boundaries were reasonably stable between 1182, when it ceded western areas to the new county of Lancashire, and 1889 when administrative counties were created, which saw some adjustments to the boundaries with County Durham, Lancashire and Lincolnshire. After 1889 there were occasional adjustments to accommodate urban areas which were developing across county boundaries, such as in 1934 when Dore and Totley were transferred from Derbyshire to Yorkshire on being absorbed into the borough of Sheffield.

More significant changes in 1974 saw the historic county divided between several counties. The majority of the area was split between North Yorkshire, South Yorkshire and West Yorkshire, which all kept the Yorkshire name. A large part of the east of the county went to the new county of Humberside, and an area in the north-east went to the new county of Cleveland. Some more rural areas at the edges of the historic county were transferred to County Durham, Cumbria, Lancashire and Greater Manchester, whilst South Yorkshire also included areas which had been in Nottinghamshire.

Cleveland and Humberside were both abolished in 1996, since when there have been four ceremonial counties with Yorkshire in their names: East Riding of Yorkshire, North Yorkshire, South Yorkshire and West Yorkshire, which together cover most of the historic county.

There is a region called Yorkshire and the Humber which covers a similar area to the combined area of the four Yorkshire ceremonial counties, the exceptions being that the region excludes the parts of North Yorkshire which had been in Cleveland, but includes North East Lincolnshire and North Lincolnshire (which had been in Humberside). Until 2009, some government powers in the region were devolved to the Yorkshire and Humber Assembly; since 2009 the region has been used primarily for presentation of statistics.^{[citation needed]}