Northumbrian Water Group plc (NWG) is the holding company for several companies in the water supply, sewerage and waste water industries. Its largest subsidiary is Northumbrian Water Limited (NWL), which is one of ten companies in England and Wales that are regulated water supply and sewerage utilities. NWL is the principal water supplier in the north-east of England, where it trades as Northumbrian Water, and also supplies water to part of eastern England, as Essex and Suffolk Water. In 2011 it was acquired by Cheung Kong Infrastructure Holdings.

Northumbrian Water Limited is a water company in the United Kingdom, providing mains water and sewerage services in the English counties of Northumberland, Tyne and Wear, Durham and parts of North Yorkshire, and also supplying water as Essex and Suffolk Water. It is a wholly owned subsidiary of Northumbrian Water Group.