Northavon was a district in the English county of Avon 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 Sodbury Rural District (except the parish of Alderley) and most of Thornbury Rural District (16 out of 21 parishes) in Gloucestershire. The name "Northavon" was invented in 1973, simply denoting the district's position in the county.