Counties in Iowa
Each county page says how cases move there under Iowa's rules, and lists the police agencies that serve it.
99 counties, largest first
- Polk County516,546 people · 14 agencies
- Linn County232,028 people · 9 agencies
- Scott County175,259 people · 12 agencies
- Johnson County160,044 people · 7 agencies
- Black Hawk County131,532 people · 5 agencies
- Dallas County118,457 people · 10 agencies
- Woodbury County106,649 people · 3 agencies
- Story County101,291 people · 6 agencies
- Dubuque County99,381 people · 5 agencies
- Pottawattamie County92,996 people · 4 agencies
- Warren County57,331 people · 6 agencies
- Clinton County46,002 people · 4 agencies
- Cerro Gordo County42,372 people · 3 agencies
- Muscatine County41,853 people · 6 agencies
- Marshall County39,890 people · 3 agencies
- Jasper County38,153 people · 6 agencies
- Des Moines County38,077 people · 4 agencies
- Webster County36,838 people · 4 agencies
- Sioux County36,774 people · 6 agencies
- Wapello County35,210 people · 3 agencies
- Marion County34,192 people · 4 agencies
- Lee County32,306 people · 4 agencies
- Boone County26,799 people · 5 agencies
- Benton County26,004 people · 4 agencies
- Plymouth County25,697 people · 3 agencies
- Bremer County25,296 people · 4 agencies
- Washington County22,667 people · 2 agencies
- Mahaska County21,880 people · 4 agencies
- Jones County21,253 people · 3 agencies
- Buchanan County20,883 people · 3 agencies
- Buena Vista County20,449 people · 2 agencies
- Carroll County20,303 people · 2 agencies
- Winneshiek County19,733 people · 2 agencies
- Henry County19,349 people · 3 agencies
- Jackson County19,288 people · 4 agencies
- Fayette County19,047 people · 6 agencies
- Poweshiek County18,368 people · 2 agencies
- Cedar County18,359 people · 7 agencies
- Dickinson County18,077 people · 3 agencies
- Delaware County17,674 people · 3 agencies
- Madison County17,270 people · 4 agencies
- Clayton County16,845 people · 4 agencies
- Tama County16,796 people · 4 agencies
- Iowa County16,504 people · 3 agencies
- Hardin County16,455 people · 4 agencies
- Crawford County16,237 people · 3 agencies
- Clay County16,202 people · 2 agencies
- Jefferson County15,291 people · 2 agencies
- Hamilton County14,944 people · 2 agencies
- Floyd County14,901 people · 2 agencies
- Page County14,856 people · 3 agencies
- Mills County14,793 people · 2 agencies
- Harrison County14,623 people · 2 agencies
- Kossuth County14,322 people · 2 agencies
- Allamakee County14,238 people · 4 agencies
- O'Brien County14,220 people · 2 agencies
- Butler County14,049 people · 2 agencies
- Cass County12,960 people · 2 agencies
- Wright County12,801 people · 4 agencies
- Grundy County12,361 people · 2 agencies
- Lyon County12,354 people · 2 agencies
- Appanoose County12,077 people · 2 agencies
- Union County11,829 people · 2 agencies
- Shelby County11,689 people · 2 agencies
- Chickasaw County11,663 people · 2 agencies
- Cherokee County11,369 people · 3 agencies
- Guthrie County10,782 people · 2 agencies
- Mitchell County10,650 people · 3 agencies
- Hancock County10,528 people · 3 agencies
- Louisa County10,416 people · 1 agencies
- Winnebago County10,251 people · 3 agencies
- Montgomery County10,002 people · 2 agencies
- Franklin County9,868 people · 3 agencies
- Keokuk County9,797 people · 2 agencies
- Clarke County9,574 people · 2 agencies
- Calhoun County9,562 people · 3 agencies
- Sac County9,525 people · 3 agencies
- Howard County9,415 people · 2 agencies
- Humboldt County9,409 people · 2 agencies
- Davis County9,230 people · 2 agencies
- Emmet County9,107 people · 2 agencies
- Palo Alto County8,899 people · 2 agencies
- Lucas County8,847 people · 2 agencies
- Greene County8,658 people · 2 agencies
- Monona County8,539 people · 2 agencies
- Decatur County7,655 people · 3 agencies
- Monroe County7,406 people · 2 agencies
- Adair County7,403 people · 2 agencies
- Worth County7,338 people · 1 agencies
- Van Buren County7,131 people · 1 agencies
- Pocahontas County6,819 people · 1 agencies
- Ida County6,777 people · 1 agencies
- Wayne County6,738 people · 1 agencies
- Fremont County6,522 people · 1 agencies
- Osceola County5,980 people · 2 agencies
- Taylor County5,835 people · 3 agencies
- Audubon County5,509 people · 2 agencies
- Ringgold County4,642 people · 1 agencies
- Adams County3,617 people · 1 agencies
Population: Census Bureau county population estimates, Vintage 2025 (cc-est2025-alldata), July 1, 2025.