Wansdyke was a non-metropolitan district within the County of Avon, in the west of England from 1974 to 1996. The district was formed by the Local Government Act 1972 on 1 April 1974 as part of a reform of local authorities throughout England and Wales. Under the reorganisation, the area surrounding the cities of Bath and Bristol was formed into a new county of "Avon", named after the river that ran through the area. The county was divided into six districts, one of which was formed from the areas of Keynsham and Norton-Radstock urban districts along with Bathavon Rural District and part of Clutton Rural District in Somerset. The district was named after the Wansdyke earthwork.