The West Riding of Yorkshire was one of three historic subdivisions of Yorkshire, England. From 1889 to 1974 the riding was an administrative county named County of York, West Riding. The lieutenancy at that time included the city of York and as such was named "West Riding of the County of York and the County of the City of York". The riding ceased to be used for administrative purposes in 1974, when England's local government was reformed.

Contemporary local government boundaries in Yorkshire largely do not follow those of the riding. All of South Yorkshire (except Finningley) and West Yorkshire were historically within its boundaries, as were the south-western areas of North Yorkshire (including Ripon), the Sedbergh area of Cumbria, the Barnoldswick and Slaidburn areas of Lancashire, the Saddleworth area of Greater Manchester and the part of the East Riding of Yorkshire around Goole and southwest of the River Ouse.

The West Riding encompassed 1,771,562 acres (7,169 km) from Sheffield in the south to Sedbergh in the north and from Dunsop Bridge in the west to Adlingfleet in the east.

The southern industrial district, considered in the broadest application of the term, extended northward from Sheffield to Skipton and eastward from Sheffield to Doncaster, covering less than one-half of the riding. Within this district were Barnsley, Batley, Bradford, Brighouse, Dewsbury, Doncaster, Halifax, Huddersfield, Keighley, Leeds, Morley, Ossett, Pontefract, Pudsey, Rotherham, Sheffield, Todmorden (partly in Lancashire until 1888, when fully incorporated into Yorkshire) and Wakefield. Major centres elsewhere in the riding included Harrogate and Ripon.

Within the industrial region, other urban districts included Bingley, Bolton on Dearne, Castleford, Cleckheaton, Elland, Featherstone, Handsworth, Hoyland Nether, Liversedge, Mexborough, Mirfield, Normanton, Rawmarsh, Rothwell, Saddleworth, Shipley, Skipton, Sowerby Bridge, Stanley, Swinton, Thornhill, Wath-upon-Dearne, Wombwell and Worsborough. Outside the industrial region were Goole, Ilkley, Knaresborough, Otley and Selby. The West Riding also contained a large rural area to the north including part of the Yorkshire Dales National Park (the remainder of the park being in the North Riding).

The subdivision of Yorkshire into three ridings or "thirds" (Old Norse: Þriðungr) is of Scandinavian origin. The West Riding was first recorded (in the form West Treding) in the Domesday Book of 1086.

Unlike most English counties, Yorkshire, being so large, was divided first into the three ridings (East, North and West) and, later, the city of York (which lay within the city walls and was not part of any riding). Each riding was then divided into wapentakes, a division comparable to the hundreds of southern and western England and the wards of England's four northernmost historic counties.

The administrative county was formed in 1889 by the Local Government Act 1888, and covered the historic West Riding except for the larger urban areas, which were county boroughs with the powers of both a municipal borough and a county council. Initially there were five in number: Bradford, Leeds, Huddersfield, Halifax, and Sheffield. The City of York (also a county borough) was included in the county for census and lieutenancy purposes. The number of county boroughs increased over the years; Rotherham gained this status in 1902, Barnsley and Dewsbury in 1913, Wakefield in 1915 and Doncaster in 1927. The boundaries of existing county boroughs were also widened.

Beginning in 1898, the West Riding County Council was based at the County Hall in Wakefield, which was inherited by the West Yorkshire Metropolitan County Council in 1974.

The Local Government Act 1888 included the entirety of Todmorden with the West Riding administrative county, and also in its lieutenancy area ("county"), though the postal address for Todmorden was Lancashire. Other boundary changes in the county included the expansion of the county borough of Sheffield southward in areas historically in Derbyshire such as Dore.

Fingerposts erected in the West Riding until the mid-1960s had a distinctive style. At the top of the post was a roundel in the form of a hollow circle with a horizontal line across the middle, displaying "Yorks W.R.", the name of the fingerpost's location, and a grid reference. Other counties, apart from Dorset, did not display a grid reference and did not have a horizontal bar through the roundel. From 1964, many fingerposts were replaced by ones in the modern style, but some of the old style still survive within the West Riding boundaries.

By 1971 1,924,853 people (or 50.85% of the West Riding's population) lived in the administrative county, against 1,860,435 (or 49.15%) in the ten county boroughs.

In the Domesday Book of 1086 they were eleven wapentakes, these were as follows:

Domesday name	Later name	Also known as/ division names	Other status post-Domesday
Agbrigg			Agbrigg and Morley (temporarily)
Morley		Blackston Edge, Bradfordale or Sowerbyshire
Ainsty	Ainsty of York		Joined the City of York outside the Riding system in the 15th century
Barkston	Barkston Ash		Jointly known as Elmet
Skyrack	Skyrack Upper	Airedale
	Skyrack Lower
Burghshire (of Aldborough)	Claro Upper	Wharfedale, Nidderdale, of Knaresborough, Riponshire or Kirbyshire	Liberty and Honour
	Claro Lower
Strafforth	Strafforth and Tickhill Upper	of Mexborough, of Tickhill, Hallam or Hallamshire	Liberty or Honour
	Strafforth or Tickhill Lower
Craven/ Cravenshire	Staincliffe West	Ribblesdale or Bowland	Temporarily merged into Staincliffe and Ewecross	Honour
	Staincliffe East	Staincliffe, of Skipton or Craven
Ewecross
Osgoldcross		Marshland	Liberty
Staincross

In the end of regular use, the wapentakes were: