Key takeaways
- Los Angeles County is the largest U.S. county, with 9,694,934 residents in 2025, followed by Cook County, Illinois (5,194,625) and Harris County, Texas (5,045,026).
- 50 counties had 1 million or more residents in 2025, according to the Census Bureau.
- Harris County, Texas, added 48,695 residents from 2024 to 2025 — the largest gain of any county — while Los Angeles County lost 53,934, the largest decline.
- California (15), Texas (12) and Florida (9) have the most counties on the list.
The 100 largest U.S. counties
Ranked by resident population on July 1, 2025, with July 1, 2024 population and the change. Filter by state or search.
Showing all 100 counties
| # | County | Population, 2025 | 2024 | Change |
|---|---|---|---|---|
| 1 | Los Angeles CountyCalifornia | 9,694,934 | 9,748,868 | -0.6% |
| 2 | Cook CountyIllinois | 5,194,625 | 5,188,791 | +0.1% |
| 3 | Harris CountyTexas | 5,045,026 | 4,996,331 | +1.0% |
| 4 | Maricopa CountyArizona | 4,689,558 | 4,654,147 | +0.8% |
| 5 | San Diego CountyCalifornia | 3,282,248 | 3,287,542 | -0.2% |
| 6 | Orange CountyCalifornia | 3,149,507 | 3,158,027 | -0.3% |
| 7 | Miami-Dade CountyFlorida | 2,802,029 | 2,812,144 | -0.4% |
| 8 | Dallas CountyTexas | 2,661,397 | 2,664,013 | -0.1% |
| 9 | Kings CountyNew York | 2,653,963 | 2,658,657 | -0.2% |
| 10 | Riverside CountyCalifornia | 2,544,916 | 2,529,112 | +0.6% |
| 11 | Clark CountyNevada | 2,407,226 | 2,385,746 | +0.9% |
| 12 | Queens CountyNew York | 2,358,182 | 2,367,034 | -0.4% |
| 13 | King CountyWashington | 2,344,939 | 2,317,959 | +1.2% |
| 14 | Tarrant CountyTexas | 2,248,466 | 2,230,038 | +0.8% |
| 15 | San Bernardino CountyCalifornia | 2,224,091 | 2,218,764 | +0.2% |
| 16 | Bexar CountyTexas | 2,160,088 | 2,138,942 | +1.0% |
| 17 | Broward CountyFlorida | 2,013,317 | 2,013,689 | -0.0% |
| 18 | Santa Clara CountyCalifornia | 1,914,391 | 1,907,910 | +0.3% |
| 19 | Wayne CountyMichigan | 1,769,038 | 1,765,534 | +0.2% |
| 20 | Middlesex CountyMassachusetts | 1,669,979 | 1,663,929 | +0.4% |
| 21 | New York CountyNew York | 1,664,862 | 1,665,510 | -0.0% |
| 22 | Alameda CountyCalifornia | 1,636,630 | 1,636,624 | 0.0% |
| 23 | Sacramento CountyCalifornia | 1,618,460 | 1,609,897 | +0.5% |
| 24 | Palm Beach CountyFlorida | 1,575,726 | 1,574,148 | +0.1% |
| 25 | Philadelphia CountyPennsylvania | 1,574,281 | 1,572,735 | +0.1% |
| 26 | Hillsborough CountyFlorida | 1,574,115 | 1,571,198 | +0.2% |
| 27 | Suffolk CountyNew York | 1,546,090 | 1,543,330 | +0.2% |
| 28 | Orange CountyFlorida | 1,528,002 | 1,520,988 | +0.5% |
| 29 | Bronx CountyNew York | 1,406,332 | 1,406,052 | +0.0% |
| 30 | Nassau CountyNew York | 1,398,939 | 1,397,783 | +0.1% |
| 31 | Travis CountyTexas | 1,389,670 | 1,374,921 | +1.1% |
| 32 | Franklin CountyOhio | 1,361,536 | 1,352,656 | +0.7% |
| 33 | Collin CountyTexas | 1,297,179 | 1,254,213 | +3.4% |
| 34 | Oakland CountyMichigan | 1,288,337 | 1,282,549 | +0.5% |
| 35 | Hennepin CountyMinnesota | 1,284,784 | 1,277,084 | +0.6% |
| 36 | Wake CountyNorth Carolina | 1,257,235 | 1,229,475 | +2.3% |
| 37 | Mecklenburg CountyNorth Carolina | 1,233,383 | 1,206,829 | +2.2% |
| 38 | Cuyahoga CountyOhio | 1,232,925 | 1,233,614 | -0.1% |
| 39 | Allegheny CountyPennsylvania | 1,225,035 | 1,227,174 | -0.2% |
| 40 | Salt Lake CountyUtah | 1,220,916 | 1,217,454 | +0.3% |
| 41 | Contra Costa CountyCalifornia | 1,170,070 | 1,169,534 | +0.1% |
| 42 | Fairfax CountyVirginia | 1,167,873 | 1,159,806 | +0.7% |
| 43 | Fulton CountyGeorgia | 1,098,791 | 1,090,468 | +0.8% |
| 44 | Pima CountyArizona | 1,074,685 | 1,073,456 | +0.1% |
| 45 | Montgomery CountyMaryland | 1,074,582 | 1,073,045 | +0.1% |
| 46 | Denton CountyTexas | 1,069,346 | 1,046,226 | +2.2% |
| 47 | Duval CountyFlorida | 1,062,963 | 1,054,732 | +0.8% |
| 48 | Fresno CountyCalifornia | 1,035,456 | 1,033,698 | +0.2% |
| 49 | Gwinnett CountyGeorgia | 1,018,099 | 1,009,864 | +0.8% |
| 50 | Westchester CountyNew York | 1,015,743 | 1,009,165 | +0.7% |
| 51 | Capitol Planning RegionConnecticut | 994,115 | 989,194 | +0.5% |
| 52 | Marion CountyIndiana | 992,196 | 990,213 | +0.2% |
| 53 | St. Louis CountyMissouri | 990,911 | 991,666 | -0.1% |
| 54 | Honolulu CountyHawaii | 988,703 | 990,142 | -0.1% |
| 55 | Bergen CountyNew Jersey | 977,026 | 973,477 | +0.4% |
| 56 | Fort Bend CountyTexas | 975,191 | 951,028 | +2.5% |
| 57 | Prince George's CountyMaryland | 970,374 | 964,596 | +0.6% |
| 58 | Pinellas CountyFlorida | 948,563 | 960,397 | -1.2% |
| 59 | Erie CountyNew York | 946,741 | 947,783 | -0.1% |
| 60 | Pierce CountyWashington | 946,288 | 939,786 | +0.7% |
| 61 | DuPage CountyIllinois | 934,298 | 932,651 | +0.2% |
| 62 | Kern CountyCalifornia | 927,068 | 924,648 | +0.3% |
| 63 | Milwaukee CountyWisconsin | 924,216 | 924,323 | -0.0% |
| 64 | Hidalgo CountyTexas | 921,549 | 913,612 | +0.9% |
| 65 | Shelby CountyTennessee | 910,226 | 915,438 | -0.6% |
| 66 | Essex CountyNew Jersey | 896,379 | 891,241 | +0.6% |
| 67 | Worcester CountyMassachusetts | 888,502 | 883,722 | +0.5% |
| 68 | Macomb CountyMichigan | 886,221 | 882,497 | +0.4% |
| 69 | Middlesex CountyNew Jersey | 883,335 | 881,620 | +0.2% |
| 70 | El Paso CountyTexas | 877,858 | 879,894 | -0.2% |
| 71 | Montgomery CountyPennsylvania | 877,643 | 875,160 | +0.3% |
| 72 | Lee CountyFlorida | 875,607 | 861,667 | +1.6% |
| 73 | Polk CountyFlorida | 874,790 | 851,434 | +2.7% |
| 74 | Snohomish CountyWashington | 870,656 | 861,070 | +1.1% |
| 75 | Baltimore CountyMaryland | 847,650 | 848,438 | -0.1% |
| 76 | Hamilton CountyOhio | 838,418 | 837,859 | +0.1% |
| 77 | Ventura CountyCalifornia | 830,851 | 833,431 | -0.3% |
| 78 | Essex CountyMassachusetts | 826,653 | 826,170 | +0.1% |
| 79 | San Francisco CountyCalifornia | 826,079 | 820,945 | +0.6% |
| 80 | San Joaquin CountyCalifornia | 823,815 | 817,149 | +0.8% |
| 81 | Oklahoma CountyOklahoma | 822,125 | 818,198 | +0.5% |
| 82 | Multnomah CountyOregon | 795,391 | 794,472 | +0.1% |
| 83 | Jefferson CountyKentucky | 795,222 | 794,166 | +0.1% |
| 84 | Cobb CountyGeorgia | 793,345 | 788,879 | +0.6% |
| 85 | Suffolk CountyMassachusetts | 791,891 | 793,535 | -0.2% |
| 86 | Montgomery CountyTexas | 781,194 | 751,183 | +4.0% |
| 87 | DeKalb CountyGeorgia | 774,394 | 772,584 | +0.2% |
| 88 | Utah CountyUtah | 759,859 | 745,668 | +1.9% |
| 89 | El Paso CountyColorado | 757,040 | 752,356 | +0.6% |
| 90 | Williamson CountyTexas | 752,827 | 729,013 | +3.3% |
| 91 | Monroe CountyNew York | 750,506 | 750,294 | +0.0% |
| 92 | Davidson CountyTennessee | 745,904 | 736,623 | +1.3% |
| 93 | San Mateo CountyCalifornia | 743,568 | 740,627 | +0.4% |
| 94 | Denver CountyColorado | 740,613 | 741,591 | -0.1% |
| 95 | Norfolk CountyMassachusetts | 739,749 | 737,601 | +0.3% |
| 96 | Hudson CountyNew Jersey | 735,033 | 731,028 | +0.6% |
| 97 | Jackson CountyMissouri | 732,994 | 729,123 | +0.5% |
| 98 | Lake CountyIllinois | 719,339 | 718,490 | +0.1% |
| 99 | Will CountyIllinois | 712,253 | 708,980 | +0.5% |
| 100 | Tulsa CountyOklahoma | 698,782 | 694,682 | +0.6% |
Selling to county government
Counties run some of the biggest and most varied operations in local government: sheriffs and jails, courts, elections, public health, human services, roads, parks, property assessment and, in many places, hospitals, airports and utilities. Large counties have their own procurement departments, publish budgets and capital plans, and approve major contracts in public board meetings.
- Know the elected offices. Many county departments are run by independently elected officials — sheriffs, clerks, assessors, treasurers — who set their own priorities and budgets.
- Time it to the budget. Most large counties adopt budgets months before the fiscal year starts. See our city and county budget calendars.
- Use cooperative contracts. Counties often buy through cooperative purchasing contracts to skip a full bid. See our cooperative contracts guide.
Read more about selling to state and local government, or size your market with the B2G market size calculator.
About this data
Populations are the Census Bureau's Vintage 2025 estimates of resident population for July 1, 2025 and July 1, 2024, released in March 2026. Percent change is calculated from those two estimates. Connecticut's county-equivalent planning regions are counted as the Census Bureau defines them.
Sources
- U.S. Census Bureau, Vintage 2025 Population Estimates: Annual Estimates of the Resident Population for Counties (CO-EST2025-ALLDATA)
- U.S. Census Bureau, Vintage 2025 county population estimates press release (March 2026)
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