Which county is the largest?
Los Angeles County, CA had 9,694,934 people on July 1, 2025, the most of the 3,144 counties in the fifty states and the District, according to Census Bureau population estimates — counties and Puerto Rico municipios, with components of change.
The next is Cook County, IL, with 5,194,625.
Data retrieved
The figures behind this
| County | Population |
|---|---|
| Los Angeles County, CA | 9,694,934 |
| Cook County, IL | 5,194,625 |
| Harris County, TX | 5,045,026 |
| Maricopa County, AZ | 4,689,558 |
| San Diego County, CA | 3,282,248 |
| Orange County, CA | 3,149,507 |
| Miami-Dade County, FL | 2,802,029 |
| Dallas County, TX | 2,661,397 |
| Kings County, NY | 2,653,963 |
| Riverside County, CA | 2,544,916 |
| Clark County, NV | 2,407,226 |
| Queens County, NY | 2,358,182 |
| King County, WA | 2,344,939 |
| Tarrant County, TX | 2,248,466 |
| San Bernardino County, CA | 2,224,091 |
| Bexar County, TX | 2,160,088 |
| Broward County, FL | 2,013,317 |
| Santa Clara County, CA | 1,914,391 |
| Wayne County, MI | 1,769,038 |
| Middlesex County, MA | 1,669,979 |
| New York County, NY | 1,664,862 |
| Alameda County, CA | 1,636,630 |
| Sacramento County, CA | 1,618,460 |
| Palm Beach County, FL | 1,575,726 |
| Philadelphia County, PA | 1,574,281 |
Where to go next
Sources
- Census Bureau population estimates — counties and Puerto Rico municipios, with components of change — U.S. Census Bureau · U.S. Government work · retrieved September 25, 2026