Humanities › Geography Largest Counties by Population Share Flipboard Email Print Getty Images / Kenny Hung Photography Geography Population Basics Physical Geography Political Geography Country Information Key Figures & Milestones Maps Urban Geography By Matt Rosenberg Geography Expert M.A., Geography, California State University - Northridge B.A., Geography, University of California - Davis Matt Rosenberg is an award-winning geographer and the author of "The Handy Geography Answer Book" and "The Geography Bee Complete Preparation Handbook." our editorial process Matt Rosenberg Updated July 28, 2019 Forty-three counties in the United States have a population greater than 1 million, ranked by population. The data for this list is based on mid-2016 population estimates from the United States Census Bureau. In 2010, only 39 counties in the United States had a population of more than 1 million, and Los Angeles County had fewer than 10 million residents. The top five list remains the same as in 2010. From this list, you can see that although much of the country's population is concentrated in the megalopolis region of the Northeast, there is considerable population in the metropolitan regions of the Sun Belt from Texas to California. These heavily populated cities of Texas, Arizona, and California continue to experience phenomenal growth as population declines in places like the Rust Belt continue. Largest Counties by Population Los Angeles County, CA: 10,116,705 Cook County, IL: 5,246,456 Harris County, TX: 4,441,370 Maricopa County, AZ: 4,087,191 San Diego County, California: 3,263,431 Orange County, California: 3,145,515 Miami-Dade County, Florida: 2,662,874 Kings County, New York: 2,621,793 Dallas County, Texas: 2,518,638 Riverside County, California: 2,329,271 Queens County, New York: 2,321,580 San Bernardino County, California: 2,112,619 King County, Washington: 2,079,967 Clark County, Nevada: 2,069,681 Tarrant County, Texas: 1,945,360 Santa Clara County, California: 1,894,605 Broward County, Florida: 1,869,235 Bexar County, Texas: 1,855,866 Wayne County, Michigan: 1,764,804 New York County, New York: 1,636,268 Alameda County, California: 1,610,921 Middlesex County, Massachusetts: 1,570,315 Philadelphia County, Pennsylvania: 1,560,297 Suffolk County, New York: 1,502,968 Sacramento County, California: 1,482,026 Bronx County, New York: 1,438,159 Palm Beach County, Florida: 1,397,710 Nassau County, New York: 1,358,627 Hillsborough County, Florida: 1,316,298 Cuyahoga County, Ohio: 1,259,828 Orange County, Florida: 1,253,001 Oakland County, Michigan: 1,237,868 Franklin County, Ohio: 1,231,393 Allegheny County, Pennsylvania: 1,231,255 Hennepin County, Minnesota: 1,212,064 Travis County, Texas: 1,151,145 Fairfax County, Virginia: 1,137,538 Contra Costa County, California: 1,111,339 Salt Lake County, Utah: 1,091,742 Montgomery County, Maryland: 1,030,447 Mecklenburg County, North Carolina: 1,012,539 Pima County, Arizona: 1,004,516 St. Louis County, Missouri: 1,001,876 Cite this Article Format mla apa chicago Your Citation Rosenberg, Matt. "Largest Counties by Population." ThoughtCo, Aug. 28, 2020, thoughtco.com/largest-counties-by-population-1435134. Rosenberg, Matt. (2020, August 28). Largest Counties by Population. Retrieved from https://www.thoughtco.com/largest-counties-by-population-1435134 Rosenberg, Matt. "Largest Counties by Population." ThoughtCo. https://www.thoughtco.com/largest-counties-by-population-1435134 (accessed April 15, 2021). copy citation