US counties starting with I
30 counties and county-equivalents, which is under 1% of the 3,144 in the United States. They are spread across 19 states. Sort any column, or select a county for its map and full data.
Every county beginning with I
| Name | State | Population | Land area | Density | Median income | Seat | FIPS |
|---|---|---|---|---|---|---|---|
| Iberia Parish | Louisiana | 66,846 | 574.7 sq mi | 116 per sq mi | $56,961 | New Iberia | 22045 |
| Iberville Parish | Louisiana | 29,579 | 617.3 sq mi | 47.9 per sq mi | $54,000 | Plaquemine | 22047 |
| Ida County | Iowa | 6,777 | 431.5 sq mi | 15.7 per sq mi | $63,073 | Ida Grove | 19093 |
| Idaho County | Idaho | 17,874 | 8,477 sq mi | 2.1 per sq mi | $66,325 | Grangeville | 16049 |
| Imperial County | California | 181,411 | 4,175 sq mi | 43.4 per sq mi | $57,681 | El Centro | 06025 |
| Independence County | Arkansas | 38,785 | 763.7 sq mi | 50.8 per sq mi | $56,609 | Batesville | 05063 |
| Indian River County | Florida | 172,799 | 502.6 sq mi | 344 per sq mi | $73,491 | Vero Beach | 12061 |
| Indiana County | Pennsylvania | 82,878 | 827.4 sq mi | 100 per sq mi | $60,208 | Indiana | 42063 |
| Ingham County | Michigan | 289,709 | 556.1 sq mi | 521 per sq mi | $65,526 | Mason | 26065 |
| Inyo County | California | 18,158 | 10,197 sq mi | 1.8 per sq mi | $73,991 | Independence | 06027 |
| Ionia County | Michigan | 66,557 | 571.3 sq mi | 116 per sq mi | $75,611 | Ionia | 26067 |
| Iosco County | Michigan | 25,266 | 549.5 sq mi | 46.0 per sq mi | $50,066 | Tawas City | 26069 |
| Iowa County | Iowa | 16,504 | 586.5 sq mi | 28.1 per sq mi | $71,223 | Marengo | 19095 |
| Iowa County | Wisconsin | 23,951 | 762.7 sq mi | 31.4 per sq mi | $82,182 | Dodgeville | 55049 |
| Iredell County | North Carolina | 211,798 | 574.5 sq mi | 369 per sq mi | $81,419 | Statesville | 37097 |
| Irion County | Texas | 1,463 | 1,052 sq mi | 1.4 per sq mi | $70,357 | Mertzon | 48235 |
| Iron County | Michigan | 11,757 | 1,166 sq mi | 10.1 per sq mi | $55,940 | Crystal Falls | 26071 |
| Iron County | Missouri | 9,318 | 550.3 sq mi | 16.9 per sq mi | $48,850 | Ironton | 29093 |
| Iron County | Utah | 67,141 | 3,296 sq mi | 20.4 per sq mi | $66,247 | Parowan | 49021 |
| Iron County | Wisconsin | 6,127 | 758.2 sq mi | 8.1 per sq mi | $60,625 | Hurley | 55051 |
| Iroquois County | Illinois | 26,150 | 1,117 sq mi | 23.4 per sq mi | $66,255 | Watseka | 17075 |
| Irwin County | Georgia | 9,020 | 354.4 sq mi | 25.5 per sq mi | $51,384 | Ocilla | 13155 |
| Isabella County | Michigan | 64,691 | 572.7 sq mi | 113 per sq mi | $55,237 | Mount Pleasant | 26073 |
| Isanti County | Minnesota | 44,386 | 435.8 sq mi | 102 per sq mi | $87,440 | Cambridge | 27059 |
| Island County | Washington | 85,657 | 208.7 sq mi | 410 per sq mi | $90,551 | Coupeville | 53029 |
| Isle of Wight County | Virginia | 41,321 | 315.7 sq mi | 131 per sq mi | $95,241 | Isle of Wight | 51093 |
| Issaquena County | Mississippi | 1,263 | 413 sq mi | 3.1 per sq mi | $31,429 | Mayersville | 28055 |
| Itasca County | Minnesota | 45,404 | 2,667 sq mi | 17.0 per sq mi | $68,603 | Grand Rapids | 27061 |
| Itawamba County | Mississippi | 24,152 | 532.8 sq mi | 45.3 per sq mi | $55,546 | Fulton | 28057 |
| Izard County | Arkansas | 14,405 | 580.2 sq mi | 24.8 per sq mi | $49,405 | Melbourne | 05065 |
Sources: US Census Bureau, Population Estimates Program, Vintage 2025 Population Estimates, released 26 March 2026; US Census Bureau, Gazetteer Files, 2025 Gazetteer Files, released 10 September 2025; US Census Bureau, American Community Survey, American Community Survey 2020-2024 5-Year Estimates, released 29 January 2026. Retrieved 30 August 2026.