In England, a unitary authority or unitary council is a type of local authority responsible for all local government services in an area. They combine the functions of a non-metropolitan county council and a non-metropolitan district council, which elsewhere in England provide two tiers of local government.
The district that is governed by a unitary authority is commonly referred to as a unitary authority area or unitary area. The terms unitary district and, for those which are coterminous with a county, unitary county are also sometimes used. The term unitary authority is also sometimes used to refer to the area governed, such as in the ISO 3166-2:GB standard defining a taxonomy for subdivisions of the UK, and in colloquial usage.