Western Valley is a civil parish in the eastern part of the Vale of White Horse district of Oxfordshire, England, to the east of Harwell and the west of Didcot.

[1][2] It is bordered by the civil parishes of Harwell, Milton and Sutton Courtenay in Vale of White Horse; and by: Didcot and West Hagbourne, both being in South Oxfordshire.

The parish lies wholly within the Blewbury & Harwell ward of Vale of White Horse District Council, the Hendreds & Harwell Division of Oxfordshire County Council, and the Didcot and Wantage parliamentary constituency.

Elections to the eight seats on the new parish council were to be held on 4 May 2023,[3] but only one valid nomination was received by the returning officer.

In the centre of this, and also partially within Didcot, is a large open space known as Boundary Park.