Unitary authorities of England are local authorities that are responsible for the provision of all local government services within a district. They are constituted under the Local Government Act 1992, which amended the Local Government Act 1972 to allow the existence of counties that do not have multiple districts. They typically allow large towns to have separate local authorities from the less urbanised parts of their counties and provide a single authority for small counties where division into districts would be impractical. Unitary authorities do not cover all of England. Most were established during the 1990s and a further tranche were created in 2009. Unitary authorities have the powers and functions that are elsewhere separately administered by councils of non-metropolitan counties and the non-metropolitan districts within them.
The term "unitary authority" was first used in the Redcliffe-Maud Report in 1969 in its current sense of a local government authority which combines the functions of a county council and a district council. Strictly speaking, the term does not necessarily mean a single level of local government within an area, because in some cases there are also parish councils in the same area.
Although the term was not applied to them, county boroughs between 1889 and 1974 were effectively unitary authorities, that is, single-tier administrative units. Before 1889, local government authorities had different powers and functions, but from medieval times some cities and towns had a high degree of autonomy as counties corporate. Some smaller settlements also enjoyed some degree of autonomy from regular administration as boroughs or liberties.
The Local Government Act 1972 created areas for local government where large towns and their rural hinterlands were administered together. The concept of unitary units was abandoned with a two-tier arrangement of county and district councils in all areas of England, except the Isles of Scilly where the small size and distance from the mainland made it impractical. In 1986 a broadly unitary system of local government was introduced in the six metropolitan counties and Greater London, where the upper-tier authorities were abolished and their functions were split between central government, the borough councils and joint boards.
A review in the 1990s was initiated to select non-metropolitan areas where new unitary authorities could be created. The resulting structural changes were implemented between 1995 and 1998. Bristol, Herefordshire, the Isle of Wight and Rutland were established as counties of a single district; the district councils of Berkshire became unitary; the counties of Avon, Humberside and Cleveland were broken up to create several unitary authorities; and a number of districts were split off from their associated counties. The changes caused the ceremonial counties to be defined separately, as they had been before 1974. The review caused 46 unitary authorities to be created.
A further review was initiated in 2007 and was enacted in 2009. The review established Cornwall and Northumberland as counties of a single district; established unitary authorities in County Durham, Shropshire and Wiltshire covering the part of the county that was not already split off in the 1990s review; and divided the remainder of Bedfordshire and Cheshire into two unitary authorities. The review caused nine unitary authorities to be created.
In 2017, it was proposed that two unitary authorities be formed to cover the ceremonial county of Dorset. One of the authorities would consist of the existing unitary authorities of Bournemouth, Poole and the non-metropolitan district of Christchurch, the other would be composed of the remainder of the county.  In November 2017, Secretary of State for Communities and Local Government, Sajid Javid stated that he was "minded to approve the proposals" and a final decision to implement the two unitary authority model was confirmed in February 2018.
Two competing plans were drawn up for Buckinghamshire. One plan would see the abolition of the four district councils resulting in the existing county council becoming a unitary authority. The other plan would see the formation of two unitary authorities, one authority would be formed through the merger of the three existing districts of Chiltern, South Bucks Wycombe with the other formed by the existing Aylesbury Vale district becoming a unitary authority.   In March 2016, Communities Secretary Sajid Javid indicated that the single unitary authority option would be pursued over the two unitary authority model. 
In late 2017, plans were drawn up for local government reorganisation in Northamptonshire which would see the existing eight councils in the county consolidated into a single unitary authority with a view to saving £29 million per year.  In March 2018, an independent report commissioned by the Communities Secretary suggested that a two unitary authority model should be pursued instead of a single unitary authority model. This would see the existing county council and district councils abolished and two new unitary authorities created covering the north and the south of the county.  The southern authority would consist of the existing districts of Daventry, Northampton and South Northamptonshire and the northern authority would consist of Corby, East Northamptonshire, Kettering and Wellingborough districts. 
In 2016, Oxfordshire County Council put forward a 'One Oxfordshire' proposal which would see Oxford City Council and the four other district councils in Oxfordshire abolished and replaced with a single unitary county council for Oxfordshire. In 2017, Oxford City Council voiced their opposition to the proposal. A decision on whether the proposal will go ahead was to have been announced in March 2017.
Unitary authorities combine the powers and functions that are normally delivered separately by the councils of non-metropolitan counties and non-metropolitan districts. These functions are housing, waste management, waste collection, council tax collection, education, libraries, social services, transport, planning, consumer protection, licensing, cemeteries and crematoria. The breakdown of these services is as follows:
|Service||Non-metropolitan county||Non-metropolitan district||Unitary authority|
|Leisure and recreation|
Most unitary authorities are divided into a number of multiple member wards from which councillors are elected in the same way as in two-tier district council elections. The exceptions, which are divided into electoral divisions as in county council elections, are Cornwall, County Durham, the Isle of Wight, Northumberland, Shropshire and Wiltshire.
|District||Local authority||Created||Formed by|
|Bath and North East Somerset||Bath and North East Somerset Council||1996||District gained county functions|
|Bedford||Bedford Borough Council||2009||District gained county functions|
|Blackburn with Darwen||Blackburn with Darwen Borough Council||1998||District gained county functions|
|Blackpool||Blackpool Council||1998||District gained county functions|
|Bournemouth||Bournemouth Borough Council||1997||District gained county functions|
|Bracknell Forest||Bracknell Forest Borough Council||1998||District gained Berkshire county functions|
|Brighton and Hove||Brighton and Hove City Council||1997||District gained county functions|
|Bristolcerem||Bristol City Council||1996||District gained county functions|
|Central Bedfordshire||Central Bedfordshire Council||2009||Districts merged and gained county functions|
|Cheshire East||Cheshire East Council||2009||District gained county functions|
|Cheshire West and Chester||Cheshire West and Chester Council||2009||District gained county functions|
|Cornwallcerem||Cornwall Council||2009||County gained district functions|
|County Durhamcerem||Durham County Council||2009||County gained district functions|
|Darlington||Darlington Borough Council||1997||District gained county functions|
|Derby||Derby City Council||1997||District gained county functions|
|East Riding of Yorkshirecerem||East Riding of Yorkshire Council||1996||District gained county functions|
|Halton||Halton Borough Council||1998||District gained county functions|
|Hartlepool||Hartlepool Borough Council||1996||District gained county functions|
|Herefordshirecerem||Herefordshire Council||1998||District gained county functions|
|Isle of Wightcerem||Isle of Wight Council||1995||County gained district functions|
|Kingston upon Hull||Hull City Council||1996||District gained county functions|
|Leicester||Leicester City Council||1997||District gained county functions|
|Luton||Luton Borough Council||1997||District gained county functions|
|Medway||Medway Council||1998||District gained county functions|
|Middlesbrough||Middlesbrough Borough Council||1996||District gained county functions|
|Milton Keynes||Milton Keynes Council||1997||District gained county functions|
|North East Lincolnshire||North East Lincolnshire Council||1996||District gained county functions|
|North Lincolnshire||North Lincolnshire Council||1996||District gained county functions|
|North Somerset||North Somerset Council||1996||District gained county functions|
|Northumberlandcerem||Northumberland County Council||2009||County gained district functions|
|Nottingham||Nottingham City Council||1998||District gained county functions|
|Peterborough||Peterborough City Council||1998||District gained county functions|
|Plymouth||Plymouth City Council||1998||District gained county functions|
|Poole||Poole Borough Council||1997||District gained county functions|
|Portsmouth||Portsmouth City Council||1997||District gained county functions|
|Reading||Reading Borough Council||1998||District gained Berkshire county functions|
|Redcar and Cleveland||Redcar and Cleveland Borough Council||1996||District gained county functions|
|Rutlandcerem||Rutland County Council||1997||District gained county functions|
|Shropshirecerem||Shropshire Council||2009||County gained district functions|
|Slough||Slough Borough Council||1998||District gained Berkshire county functions|
|Southampton||Southampton City Council||1997||District gained county functions|
|Southend-on-Sea||Southend-on-Sea Borough Council||1998||District gained county functions|
|South Gloucestershire||South Gloucestershire Council||1996||District gained county functions|
|Stockton-on-Tees||Stockton-on-Tees Borough Council||1996||District gained county functions|
|Stoke-on-Trent||Stoke-on-Trent City Council||1998||District gained county functions|
|Swindon||Swindon Borough Council||1998||District gained county functions|
|Telford and Wrekin||Telford and Wrekin Borough Council||1998||District gained county functions|
|Thurrock||Thurrock Council||1998||District gained county functions|
|Torbay||Torbay Council||1998||District gained county functions|
|Warrington||Warrington Borough Council||1998||District gained county functions|
|West Berkshire||West Berkshire Council||1998||District gained Berkshire county functions|
|Wiltshirecerem||Wiltshire Council||2009||County gained district functions|
|Windsor and Maidenhead||Windsor and Maidenhead Borough Council||1998||District gained Berkshire county functions|
|Wokingham||Wokingham Borough Council||1998||District gained county functions|
|York||City of York Council||1996||Districts merged and gained county functions|
Parts of this article (those related to combined authorities for metropolitan boroughs) need to be updated.(August 2015)
The Council of the Isles of Scilly is a sui generis single-tier authority, created in 1890 and since 1930 has held the "powers, duties and liabilities" of a county council. It thus is not a Unitary Authority as those are such authorities created under the Local Government Act 1992. The 36 metropolitan borough councils are also the sole elected local government units in their areas (except for parish councils in a few locations), but share strategic functions with joint boards and arrangements. On the other hand, the City of London Corporation and the 32 London borough councils, although they have a high degree of autonomy, share strategic functions with the directly elected Mayor of London and London Assembly.