Largest Counties by Population in the United States

Largest Counties by Population in the United States 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 countrys 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: 10,116,705Cook County, IL: 5,246,456Harris County, TX: 4,441,370Maricopa County, AZ: 4,087,191San Diego County, California: 3,263,431Orange County, California: 3,145,515Miami-Dade County, Florida: 2,662,874Kings County, New York: 2,621,793Dallas County, Texas: 2,518,638Riverside County, California: 2,329,271Queens County, New York: 2,321,580San Bernardino County, California: 2,112,619King County, Washington: 2,079,967Clark County, Nevada: 2,069,681Tarrant County, Texas: 1,945,360Santa Clara County, California: 1,894,605Broward County, Florida: 1,869,235Bexar County, Texas: 1,855,866Wayne County, Michigan: 1,764,804New York County, New York: 1,636,268Alameda County, California: 1,610,921Middlesex County, Massachusetts: 1,570,315Philadelphia County, Pennsylvania: 1,560,297Suffolk County, New York: 1,502,968Sacramento County, California: 1,482,026Bronx County, New York: 1,438,159Palm Beach County, Florida: 1,397,710Nassau County, New York: 1,358,627Hillsborough C ounty, Florida: 1,316,298 Cuyahoga County, Ohio: 1,259,828Orange County, Florida: 1,253,001Oakland County, Michigan: 1,237,868Franklin County, Ohio: 1,231,393Allegheny County, Pennsylvania: 1,231,255Hennepin County, Minnesota: 1,212,064Travis County, Texas: 1,151,145Fairfax County, Virginia: 1,137,538Contra Costa County, California: 1,111,339Salt Lake County, Utah: 1,091,742Montgomery County, Maryland: 1,030,447  Mecklenburg County, North Carolina: 1,012,539Pima County, Arizona: 1,004,516  St. Louis County, Missouri: 1,001,876