New Haven County is a county in the south central part of the U.S. state of Connecticut. As of the 2020 census, the population was 864,835, making it the third-most populous county in Connecticut. Two of the state's top 5 largest cities, New Haven (3rd) and Waterbury (5th), are part of New Haven County.
In the United States, a county or county equivalent is an administrative or political subdivision of a U.S. state or other territories of the United States which consists of a geographic area with specific boundaries and usually 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. The specific governmental powers of counties 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; New York City is uniquely partitioned into five counties, referred to at the city government level as boroughs. 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, those counties in Connecticut, Rhode Island, eight of Massachusetts's 14 counties, and Alaska's Unorganized Borough have no government power, existing only as geographic distinctions.
Watertown is a town in Litchfield County, Connecticut, United States. The town is part of the Naugatuck Valley Planning Region. The population was 22,105 at the 2020 census. The ZIP Codes for Watertown are 06795 and 06779. It is a suburb of Waterbury. The urban center of the town is the Watertown census-designated place, with a population of 3,938 at the 2020 census.
Middlebury is a town in New Haven County, Connecticut, United States. The population was 7,574 at the 2020 census. The town is part of the Naugatuck Valley Planning Region.
Prospect is a town in the Naugatuck Valley Planning Region, Connecticut, United States. It is a suburb of the nearby city of Waterbury to its north, and is on the north-eastern fringes of the New York metropolitan area. The population was estimated to be 9,401 in 2020. Prospect is part of the Waterbury NECTA and of the historical New Haven County. Prospect is also a member of the regional health district Chesprocott, along with Cheshire and Wolcott.
Naugatuck is a consolidated borough and town in New Haven County, Connecticut, United States. The town, part of the Naugatuck Valley Planning Region, had a population of 31,519 as of the 2020 Census.
Stamford-Bridgeport-Norwalk is a metropolitan area in the U.S. state of Connecticut. The area is located in Southwestern Connecticut. In its most conservative form the area consists of the city of Bridgeport and five surrounding towns—Easton, Fairfield, Monroe, Stratford, and Trumbull. This definition of the Stamford area has a population of more than 305,000 and is within the Stamford -Bridgeport-Norwalk-Danbury metropolitan statistical area, which consists of all of Fairfield County, Connecticut. The estimated 2015 county population was 948,053. The area is numbered as part of the New York-Newark Combined Statistical Area NY-NJ-CT-PA by the United States Census Bureau.
Connecticut shares with the five other New England states a governmental structure known as the New England town. From 1666 to 1960, Connecticut had a system of county governments, which each had limited powers given to it by the General Assembly. They were abolished by Public Act 152 in 1960. Connecticut also had a system of sheriffs' offices until October 2000, when those were also abolished.
The Central Naugatuck Valley is a region of Connecticut in New Haven and Litchfield counties located approximately 70 miles (110 km) northeast of New York City and 110 miles (180 km) southwest of Boston, United States. The region comprises 13 towns: Beacon Falls, Bethlehem, Cheshire, Middlebury, Naugatuck, Oxford, Prospect, Southbury, Thomaston, Waterbury, Watertown, Wolcott, and Woodbury.
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 Northeastern Connecticut Planning Region is a planning region and county-equivalent in Connecticut. It is served by the coterminous Northeastern Connecticut Council of Governments (NECCOG). In 2022, planning regions were approved to replace Connecticut's counties as county-equivalents for statistical purposes, with full implementation occurring by 2024.
The Capitol Planning Region is a planning region and county-equivalent in Connecticut. It is served by the coterminous Capitol Region Council of Governments (CRCOG). In 2022, planning regions were approved to replace Connecticut's counties as county-equivalents for statistical purposes, with full implementation occurring by 2024.
The Greater Bridgeport Planning Region is a planning region and county-equivalent in Connecticut. It is served by the coterminous Connecticut Metropolitan Council of Governments (MetroCOG). In 2022, planning regions were approved to replace Connecticut's counties as county-equivalents for statistical purposes, with full implementation occurring by 2024.
The Lower Connecticut River Valley Planning Region is a planning region and county-equivalent in Connecticut. It is served by the coterminous Lower Connecticut River Valley Council of Governments (RiverCOG). In 2022, planning regions were approved to replace Connecticut's counties as county-equivalents for statistical purposes, with full implementation occurring by 2024.
The Northwest Hills Planning Region is a planning region and county-equivalent in Connecticut, United States. It is served by the coterminous Northwest Hills Council of Governments (NHCOG). In 2022, planning regions were approved to replace Connecticut's counties as county-equivalents for statistical purposes, with full implementation occurring by 2024.
The South Central Connecticut Planning Region is a planning region in the Councils of governments in Connecticut and a county-equivalent in Connecticut. It is served by the coterminous South Central Regional Council of Governments (SCRCOG). In 2022, planning regions were approved to replace Connecticut's counties as county-equivalents for statistical purposes, with full implementation occurring by 2024.
The Southeastern Connecticut Planning Region is a planning region and county-equivalent in Connecticut. It is served by the coterminous Southeastern Connecticut Council of Governments (SCCOG). In 2022, planning regions were approved to replace Connecticut's counties as county-equivalents for statistical purposes, with full implementation occurring by 2024.
The Western Connecticut Planning Region is a planning region and county-equivalent in 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, South Western CT MPO and the Housatonic Valley MPO.
United States
Connecticut 
