Largest counties of the United States by population as of the 2020 United States census

This is a list of the 100 most populous

counties A county is a geographic region of a country used for administrative or other purposesChambers Dictionary, L. Brookes (ed.), 2005, Chambers Harrap Publishers Ltd, Edinburgh in certain modern nations. The term is derived from the Old French ...

in the

United States The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country Continental United States, primarily located in North America. It consists of 50 U.S. state, states, a Washington, D.C., ...

based on the national decennial US census conducted on April 1, 2020 and vintage Census population estimates for July 1, 2021. Many of the counties on the list include major cities or metropolitan areas in all parts of the United States. Six of the listed counties have consolidated city and county government, namely the

City and County of Honolulu Honolulu County (officially known as the City and County of Honolulu, formerly Oahu County) is a consolidated city–county in the U.S. state of Hawaii. The city–county includes both the city of Honolulu (the state's capital and largest cit ...

, Metropolitan Government of Nashville and Davidson County, Tennessee, City and County of Philadelphia,

City and County of San Francisco San Francisco (; Spanish language, Spanish for "Francis of Assisi, Saint Francis"), officially the City and County of San Francisco, is the commercial, financial, and cultural center of Northern California. The city proper is the List of Ca ...

, City of Jacksonville and Duval County and City and County of Denver.

New York County Manhattan (), known regionally as the City, is the most densely populated and geographically smallest of the five boroughs of New York City. The borough is also coextensive with New York County, one of the original counties of the U.S. state ...

Bronx County The Bronx () is a borough of New York City, coextensive with Bronx County, in the state of New York. It is south of Westchester County; north and east of the New York City borough of Manhattan, across the Harlem River; and north of the New York ...

Kings County Kings County or King's County may refer to: Places Canada *Kings County, New Brunswick *Kings County, Nova Scotia *Kings County, Prince Edward Island ** King's County (electoral district), abolished in 1892 Ireland * County Offaly, formerly calle ...

, Queens County and Richmond County are coterminous with the respective

boroughs A borough is an administrative division in various English-speaking countries. In principle, the term ''borough'' designates a self-governing walled town, although in practice, official use of the term varies widely. History In the Middle A ...

New York City New York, often called New York City or NYC, is the List of United States cities by population, most populous city in the United States. With a 2020 population of 8,804,190 distributed over , New York City is also the L ...

; they fall under the jurisdiction of the combined city government.

Independent cities An independent city or independent town is a city or town that does not form part of another general-purpose local government entity (such as a province). Historical precursors In the Holy Roman Empire, and to a degree in its successor state ...

are not counted. Many of the most populous counties listed are in Southern California, Illinois, Texas and New York and roughly correspond to the most populous cities in the United States. Counties in the Western United States are typically larger, so they often have higher raw populations even with comparable population densities.

List

This list lists the most populous US counties sorted according to both the 2020 official enumeration and 2021 vintage population estimates by the United States Census Bureau (USCB).

Gallery

File:Bunker Hill Downtown Los Angeles.jpg,

Downtown Los Angeles Downtown Los Angeles (DTLA) contains the central business district of Los Angeles. In addition, it contains a diverse residential area of some 85,000 people, and covers . A 2013 study found that the district is home to over 500,000 jobs. It is a ...

, county seat of

Los Angeles County, California Los Angeles County, officially the County of Los Angeles, and sometimes abbreviated as L.A. County, is the List of the most populous counties in the United States, most populous county in the United States and in the U.S. state of California, ...

, the most populous county in the United States. County buildings and the civic center, pictured at the bottom right. File:2005-10-13 1700x3020 chicago above loop.jpg,

Downtown Chicago ''Downtown'' is a term primarily used in North America by English speakers to refer to a city's sometimes commercial, cultural and often the historical, political and geographic heart. It is often synonymous with its central business district ...

, in

Cook County, Illinois Cook County is the most populous county in the U.S. state of Illinois and the second-most-populous county in the United States, after Los Angeles County, California. More than 40% of all residents of Illinois live within Cook County. As of 2 ...

, the second-most populous county in the United States. File:Panoramic Houston skyline.jpg,

Downtown Houston Downtown is the largest central business district in the city of Houston and the largest in the state of Texas, located near the geographic center of the metropolitan area at the confluence of Interstate 10, Interstate 45, and Interstate 69. The ...

, located in

Harris County, Texas Harris County is a county located in the U.S. state of Texas; as of the 2020 census, the population was 4,731,145, making it the most populous county in Texas and the third most populous county in the United States. Its county seat is Houston, ...

, the third-most populous county in the United States. File:Phoenix skyline Arizona USA.jpg, Downtown

Phoenix, Arizona Phoenix ( ; nv, Hoozdo; es, Fénix or , yuf-x-wal, Banyà:nyuwá) is the List of capitals in the United States, capital and List of cities and towns in Arizona#List of cities and towns, most populous city of the U.S. state of Arizona, with 1 ...

, county seat of the fourth-most populous county in the United States, Maricopa. File:SANO1 015.jpg, Downtown

San Diego, California San Diego ( , ; ) is a city on the Pacific Ocean coast of Southern California located immediately adjacent to the Mexico–United States border. With a 2020 population of 1,386,932, it is the eighth most populous city in the United Stat ...

San Diego County San Diego County (), officially the County of San Diego, is a county in the southwestern corner of the U.S. state of California. As of the 2020 census, the population was 3,298,634, making it California's second-most populous county and the f ...

is the fifth-most populous county in the United States. File:Aerial view of central Orange County overlooking South Coast Metro, John Wayne Airport, and the Irvine business district.JPG, Aerial view of

Orange County, California Orange County is located in the Los Angeles metropolitan area in Southern California. As of the 2020 census, the population was 3,186,989, making it the third-most-populous county in California, the sixth-most-populous in the United States, ...

, the sixth-most populous county in the United States. File:Central Downtown Miami 20090513.jpg,

Downtown Miami Downtown Miami is the urban city center of Miami, Florida. The city's greater downtown region consists of the Central Business District, Brickell, the Historic District, Government Center, the Arts & Entertainment District, and Park West. ...

Miami-Dade County Miami-Dade County is a county located in the southeastern part of the U.S. state of Florida. The county had a population of 2,701,767 as of the 2020 census, making it the most populous county in Florida and the seventh-most populous county in ...

, the largest county in Florida, and the county seat of the seventh-most populous county in the United States. File:Greenpoint Houses.JPG, Row houses in

Brooklyn Brooklyn () is a borough of New York City, coextensive with Kings County, in the U.S. state of New York. Kings County is the most populous county in the State of New York, and the second-most densely populated county in the United States, be ...

, Kings County,

New York New York most commonly refers to: * New York City, the most populous city in the United States, located in the state of New York * New York (state), a state in the northeastern United States New York may also refer to: Film and television * '' ...

, the eighth-most populous county in the United States.

References

{{DEFAULTSORT:Most Populous Counties In The United States Populous Counties Most Populous

Counties A county is a geographic region of a country used for administrative or other purposesChambers Dictionary, L. Brookes (ed.), 2005, Chambers Harrap Publishers Ltd, Edinburgh in certain modern nations. The term is derived from the Old French ...