Largest counties by population
Rank US counties and county equivalents by resident population, not land area.
U.S. Census Bureau Population EstimatesPeriod: July 1, 2024–July 1, 2025 · Vintage 2025Retrieved 2026-10-05T08:10:35+00:00
July 1 resident population estimates from a single Census vintage. Counties are ranked by population, not land area. County equivalents include independent cities and other Census county-equivalent areas.
Ranks are competition ranks computed across the full filtered set.
| Rank | Name | State | Population | Growth |
|---|---|---|---|---|
| 101 | District of Columbia | District of Columbia | 693,645 | 0.3% |
| 102 | Providence County | Rhode Island | 678,179 | 0.5% |
| 103 | Kent County | Michigan | 675,232 | 0.7% |
| 104 | Pasco County | Florida | 674,516 | 2.8% |
| 105 | Arapahoe County | Colorado | 673,820 | -0.3% |
| 106 | Ocean County | New Jersey | 673,746 | 0.8% |
| 107 | Bernalillo County | New Mexico | 667,601 | -0.4% |
| 108 | Jefferson County | Alabama | 665,742 | -0.1% |
| 109 | Brevard County | Florida | 663,982 | 1.2% |
| 110 | Monmouth County | New Jersey | 651,035 | 0.4% |
| 111 | Bucks County | Pennsylvania | 647,828 | -0.1% |
| 112 | Western Connecticut Planning Region | Connecticut | 640,482 | 0.4% |
| 113 | Johnson County | Kansas | 636,906 | 1.0% |
| 114 | Washington County | Oregon | 611,708 | 0.5% |
| 115 | Volusia County | Florida | 606,573 | 0.9% |
| 116 | Douglas County | Nebraska | 606,460 | 0.9% |
| 117 | Anne Arundel County | Maryland | 603,380 | 0.4% |
| 118 | Union County | New Jersey | 601,863 | 0.5% |
| 119 | Bristol County | Massachusetts | 593,640 | 0.5% |
| 120 | Dane County | Wisconsin | 590,375 | 0.7% |
| 121 | New Castle County | Delaware | 588,026 | 0.3% |
| 122 | Greenville County | South Carolina | 583,125 | 1.6% |
| 123 | Delaware County | Pennsylvania | 580,937 | -0.1% |
| 124 | Jefferson County | Colorado | 580,451 | 0.0% |
| 125 | South Central Connecticut Planning Region | Connecticut | 578,741 | 0.2% |
| 126 | Baltimore city | Maryland | 569,997 | 0.0% |
| 127 | Lancaster County | Pennsylvania | 563,159 | 0.2% |
| 128 | Guilford County | North Carolina | 562,234 | 0.9% |
| 129 | Spokane County | Washington | 558,344 | 0.5% |
| 130 | Stanislaus County | California | 557,719 | 0.1% |
| 131 | Chester County | Pennsylvania | 557,116 | 0.5% |
| 132 | Adams County | Colorado | 554,668 | 1.0% |
| 133 | Plymouth County | Massachusetts | 546,829 | 0.4% |
| 134 | Ada County | Idaho | 546,141 | 2.0% |
| 135 | Ramsey County | Minnesota | 541,623 | 0.2% |
| 136 | Montgomery County | Ohio | 539,598 | 0.5% |
| 137 | Pinal County | Arizona | 539,380 | 4.6% |
| 138 | Sedgwick County | Kansas | 538,433 | 0.8% |
| 139 | Summit County | Ohio | 538,376 | 0.3% |
| 140 | Camden County | New Jersey | 535,799 | 0.4% |
| 141 | Clark County | Washington | 532,119 | 1.1% |
| 142 | Passaic County | New Jersey | 531,624 | 0.1% |
| 143 | Kane County | Illinois | 525,757 | 0.4% |
| 144 | Morris County | New Jersey | 524,251 | 0.6% |
| 145 | Polk County | Iowa | 516,546 | 0.6% |
| 146 | Knox County | Tennessee | 511,453 | 0.8% |
| 147 | Washoe County | Nevada | 509,386 | 0.8% |
| 148 | Lake County | Indiana | 504,612 | 0.4% |
| 149 | Prince William County | Virginia | 502,966 | 0.9% |
| 150 | Richmond County | New York | 501,290 | 0.3% |
3144 ranked entries.