List of counties in Connecticut in the context of Counties of the United States

In the United States, a county or county equivalent is an administrative subdivision of a state or territory, typically with defined geographic boundaries and some level of governmental authority. The term "county" is used in 48 states, while Louisiana and Alaska have functionally equivalent subdivisions called parishes and boroughs, respectively. Counties and other local governments exist as a matter of U.S. state law, so the specific governmental powers of counties may vary widely between the states, with many providing some level of services to civil townships, municipalities, and unincorporated areas. Certain municipalities are in multiple counties. Some municipalities have been consolidated with their county government to form consolidated city-counties or have been legally separated from counties altogether to form independent cities. Conversely, counties in Connecticut and Rhode Island, eight of Massachusetts's 14 counties, and Alaska's Unorganized Borough have no government power, existing only as geographic distinctions.

The United States Census Bureau uses the term "county equivalent" to describe places that are comparable to counties, but called by different names. Louisiana parishes, the organized boroughs of Alaska, independent cities, and the District of Columbia are equivalent to counties for administrative purposes. Alaska's Unorganized Borough is further divided into 11 census areas that are statistically equivalent to counties. In 2024, the U.S. Census Bureau began to also recognize Connecticut's councils of governments, which took over some of the regional powers from the state's former county governments, as county equivalents.

The Western Connecticut Planning Region is a planning region and county-equivalent in the U.S. state of Connecticut. It is served by the coterminous Western Connecticut Council of Governments (WestCOG), one of nine regional councils of governments in Connecticut. Within the region, there are two Metropolitan Planning Organizations (MPOs), South Western CT MPO and the Housatonic Valley MPO.

The region includes the Connecticut Panhandle, Greater Danbury, and the Gold Coast. In 2022, planning regions were approved to replace Connecticut's counties as county-equivalents for statistical purposes, with full implementation occurring in 2024.

In Connecticut, councils of governments, also known as COGs, are regional planning organizations that bring together the chief elected officials or professional managers from member municipalities in Connecticut. Since 2015 and 2022, the Connecticut planning regions served by COGs have been recognized as county equivalents under state and federal law respectively, superseding the eight legacy counties in the state for most federal funding and statistical purposes.

The COGs are meant to aid coordination among neighboring cities and towns, and between the towns and the state government, on issues including land use, zoning, and transportation. They serve some functions analogous to county governments in other states, but have no independent taxing authority (Connecticut disbanded county governments in 1960). Councils of government also host some intermunicipal services based on the needs and voluntary participation of member or client municipalities. Councils, or COGs, receive funding through membership dues, state grants, and federal grants.

There are 3,244 counties and county equivalents in the United States. The 50 states of the United States are divided into 3,007 political subdivisions of states called counties. Two hundred thirty-seven other local governments and geographic places are also first-order administrative divisions of their respective state/district/territory, but are not called counties. The United States Census Bureau refers to the latter as county equivalents. The 237 county equivalents include the District of Columbia and 100 equivalents in U.S. territories (such as those in Puerto Rico). The large majority of counties and equivalents were organized by 1970. Since that time, most creations, boundary changes and dissolutions have occurred in Alaska, Virginia, and Connecticut.

Among the 50 states, 44 are partitioned entirely into counties, with no county equivalents. Louisiana is instead divided into 64 equivalent parishes, while Alaska is divided into 19 equivalent boroughs and 11 sparsely populated census areas, the latter also known collectively as the unorganized borough. Virginia is composed of a mixture of 95 counties and 38 independent cities. Maryland, Missouri and Nevada are each composed entirely of counties, except that each also has exactly one independent city: Baltimore, St. Louis, and Carson City, respectively. The District of Columbia is a single federal district that is not part of any state or county. All of the above 136 exceptional cases are reckoned as county equivalents. The number of counties (or equivalents) per state ranges from the three counties of Delaware, to the 254 counties of Texas. In New England, where the town model predominates, several counties have no corresponding local governments, existing only as historical, legal, and census boundaries, such as the counties of Rhode Island, as well as eight of Massachusetts' 14 counties. On June 6, 2022, the U.S. Census Bureau formally recognized Connecticut's nine councils of government as county equivalents instead of the state's eight counties. Connecticut's eight historical counties continue to exist in name only, and are no longer considered for statistical purposes. In total, the 50 states consist of 3,144 counties and equivalents.

The town is the basic unit of local government and local division of state authority in the six New England states. Most other U.S. states lack a direct counterpart to the New England town. New England towns overlie the entire area of a state, similar to civil townships in other states where they exist, but they are fully functioning municipal corporations, possessing powers similar to cities and counties in other states. In the United States, New Jersey's system of equally powerful townships, boroughs, towns, and cities is the system which is most similar to that of New England; internationally, local government systems comparable to the New England town exist in much of Western Europe, such as the Gemeinden of Germany, the communes of France, and the freguesias of Portugal.

New England towns are often governed by a town meeting, an assembly of eligible town residents. The great majority of municipal corporations in New England are based on the town model; there, statutory forms based on the concept of a compact populated place are uncommon, though elsewhere in the U.S. they are prevalent. County government in New England states is typically weak, and in some states nonexistent. Connecticut, for example, has no county governments, nor does Rhode Island.