Yorkshire Water is a water supply and treatment utility company servicing West Yorkshire, South Yorkshire, the East Riding of Yorkshire, part of North Lincolnshire, most of North Yorkshire and part of Derbyshire, in England. The company has its origins in the Yorkshire Water Authority, one of ten regional water authorities created by the Water Act 1973, and privatised under the terms of the Water Act 1989, when Yorkshire Water plc, the parent company of the Yorkshire Water business, was floated on the London Stock Exchange. The parent company was Kelda Group in 1999. In February 2008, Kelda Group was bought by a consortium of infrastructure funds.

It is regulated under the Water Industry Act 1991.

Not taking into account human composition: In the year ending 31 March 2013, 99.93% of Yorkshire Water’s samples met the UK standards; in the previous year it was 99.95%