Біріккен қалалық және округтік билік жүйесі

U. S. local jurisdiction comprising a merged city and county

In United States local government, a consolidated city county (also known as either a city parish or a consolidated government in Louisiana, depending on the locality, or a unified municipality, unified home rule borough, or city and borough in Alaska) is formed when one or more cities and their surrounding county (parish in Louisiana, borough in Alaska) merge into one unified jurisdiction. As such it is a type of unitary authority that has the governmental powers of both a municipal corporation and a county. A consolidated city county is different from an independent city, although the latter may result from consolidation of a city and a county and may also have the same powers as a consolidated city county. An independent city is a city not deemed by its state to be located within the boundary of any county and considered a primary administrative division of its state. A consolidated city county differs from an independent city in that the city and county both nominally exist, although they have a consolidated government, whereas in an independent city, the county does not even nominally exist. Wyandotte County, Kansas, uses the term "unified government" to refer to its consolidation with Kansas City, Kansas, and most of the towns within the county boundaries remain separate jurisdictions within the county. Individual sections of a metropolitan or regional municipality may retain some autonomous jurisdiction apart from the citywide government. Often, in place of another level of government, local governments form councils of governments – essentially governmental organizations which are not empowered with any law making or law enforcement powers. This is the case in the Atlanta metropolitan area, where the Atlanta Regional Commission (ARC) studies and makes recommendations on the impact of all major construction and development projects on the region, but generally cannot stop them. The Georgia Regional Transportation Authority (GRTA) is a true government agency of the state of Georgia, and does control some state transportation funding to the cities and counties, but otherwise has very little authority beyond this small power of the purse. The case of New York City is unique, in that the city consists of five boroughs, each of which is co extensive with a county. Each has its own district attorney; however, county level government is essentially non existent as all executive and legislative power is exercised by the city government throughout the five boroughs. The city, as currently constituted, was created in 1898 when the city of New York (then comprising what would become the boroughs of Manhattan and The Bronx) annexed Kings County, Queens County, and Richmond County as the boroughs of Brooklyn, Queens, and Staten Island, respectively.

Similar unitary authority arrangements also exist in other countries. England has six "metropolitan counties" created in 1974: Greater Manchester, Merseyside, South Yorkshire, Tyne and Wear, West Midlands, and West Yorkshire. From 1986, these metropolitan counties do not have county councils but rather joint boards for certain functions. Modern unitary authorities are similar, and are known as county boroughs in Wales. In Scotland, Aberdeen, Dundee, Edinburgh and Glasgow are functionally "independent cities", though the term is not used. London is unique however, being a ceremonial county (officially known as Greater London) containing the 32 London boroughs. Enclaved within Greater London, the ancient City of London forms a distinct county, which today forms only a tiny part of what most consider to be London as a capital city, which takes up 607 square miles. The Canadian province of Ontario contains several single tier municipalities, which serve the same sort of functions as American consolidated city counties. One example is the City of Toronto, created in 1998 from the amalgamation of the central government and the six constituent municipalities of the Municipality of Metropolitan Toronto (a type of regional municipality), itself originally created in 1954. In Germany, Berlin and Hamburg are both cities and states (the state of Bremen consists of the cities of Bremen and Bremerhaven). Nearly every larger city in Germany is an independent city, like Frankfurt, Stuttgart, Munich or Dresden; Austria, where the capital of Vienna is both a city and state; France, where the capital city of Paris has been coterminous with the département of Paris since 1968; and South Korea, where Seoul is a special city, while six other cities (Busan, Daegu, Daejeon, Gwangju, Incheon, and Ulsan) are metropolitan cities. Additionally, the Australian Capital Territory government in Australia performs all municipal functions of the city of Canberra, and thus functions as an integrated city territory. Similarly, the City of Tokyo merged with the prefecture to form Tokyo metropolis in 1943.

The City of Boston and Suffolk County, Massachusetts operated with a consolidated government for most of the twentieth century with Boston providing office space, auditors, budget, personnel and financial oversight for Suffolk County. This was not a true consolidation because three municipalities – Chelsea, Revere and Winthrop – were never annexed into Boston and remained separate jurisdictions within Suffolk County; however, the City of Boston held complete control of the county by law. The special relationship between Boston and Suffolk County ended in 1999 as part of the gradual abolition of county governments through much of the state with all county employees and powers transferred to Commonwealth of Massachusetts control. The only remaining powers and duties for the City of Boston in regards to the county is ceremonial in which the Suffolk County Register of Deeds is issued the oath of office at the start of a term as well as calls for a meeting to hold a special election to fill the office should there be a failure to elect someone to the office or should a vacancy occur. From the 17th century to 1898, New York City was coterminous with New York County and was often referred to as the "City and County of New York". Both were coterminous with Manhattan until 1874, when the City and County annexed parts of Westchester County that would later become the West Bronx, later annexing the remainder of the future Bronx. Upon consolidation in 1898, New York County was coterminous and consolidated with the boroughs of the Bronx and Manhattan, while the other boroughs were consolidated with their own respective counties. The Bronx was separated from New York County in 1914 to form its own Bronx County, and since then, each of the five boroughs of New York City is coterminous and consolidated with a county of New York state.