RANKING · 2025 ESTIMATES · 99 SHOWN OF 99

Most densely populated, Iowa counties

Iowa counties ranked by residents per square mile (2025). This list covers the 99 counties in Iowa that qualify, ranked against each other statewide.

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RELATEDLargest by population Fastest growing Fastest shrinking Most population gained Most population lost Most sparsely populated

RANKPLACESTATEPOPPOPULATION DENSITYVS –

01Polk County, IAIA516,546902–

02Scott County, IAIA175,259383–

03Linn County, IAIA232,028324–

04Johnson County, IAIA160,044261–

05Black Hawk County, IAIA131,532232–

06Dallas County, IAIA118,457201–

07Story County, IAIA101,291177–

08Dubuque County, IAIA99,381163–

09Woodbury County, IAIA106,649122–

10Warren County, IAIA57,331101–

11Pottawattamie County, IAIA92,99698–

12Muscatine County, IAIA41,85396–

13Des Moines County, IAIA38,07792–

14Wapello County, IAIA35,21082–

15Cerro Gordo County, IAIA42,37275–

16Marshall County, IAIA39,89070–

17Clinton County, IAIA46,00266–

18Lee County, IAIA32,30662–

19Marion County, IAIA34,19262–

20Bremer County, IAIA25,29658–

21Jasper County, IAIA38,15352–

22Webster County, IAIA36,83851–

23Sioux County, IAIA36,77448–

24Dickinson County, IAIA18,07748–

25Boone County, IAIA26,79947–

26Henry County, IAIA19,34945–

27Washington County, IAIA22,66740–

28Mahaska County, IAIA21,88038–

29Jones County, IAIA21,25337–

30Buchanan County, IAIA20,88337–

31Benton County, IAIA26,00436–

32Carroll County, IAIA20,30336–

33Buena Vista County, IAIA20,44936–

34Jefferson County, IAIA15,29135–

35Mills County, IAIA14,79334–

36Cedar County, IAIA18,35932–

37Poweshiek County, IAIA18,36831–

38Madison County, IAIA17,27031–

39Delaware County, IAIA17,67431–

40Jackson County, IAIA19,28830–

41Plymouth County, IAIA25,69730–

42Floyd County, IAIA14,90130–

43Hardin County, IAIA16,45529–

44Winneshiek County, IAIA19,73329–

45Clay County, IAIA16,20229–

46Iowa County, IAIA16,50428–

47Union County, IAIA11,82928–

48Page County, IAIA14,85628–

49Fayette County, IAIA19,04726–

50Louisa County, IAIA10,41626–

51Hamilton County, IAIA14,94426–

52Winnebago County, IAIA10,25126–

53O'Brien County, IAIA14,22025–

54Grundy County, IAIA12,36125–

55Appanoose County, IAIA12,07724–

56Butler County, IAIA14,04924–

57Montgomery County, IAIA10,00224–

58Tama County, IAIA16,79623–

59Chickasaw County, IAIA11,66323–

60Emmet County, IAIA9,10723–

61Cass County, IAIA12,96023–

62Crawford County, IAIA16,23723–

63Mitchell County, IAIA10,65023–

64Allamakee County, IAIA14,23822–

65Clarke County, IAIA9,57422–

66Wright County, IAIA12,80122–

67Humboldt County, IAIA9,40922–

68Clayton County, IAIA16,84522–

69Lyon County, IAIA12,35421–

70Harrison County, IAIA14,62321–

71Lucas County, IAIA8,84721–

72Howard County, IAIA9,41520–

73Shelby County, IAIA11,68920–

74Cherokee County, IAIA11,36920–

75Hancock County, IAIA10,52818–

76Davis County, IAIA9,23018–

77Worth County, IAIA7,33818–

78Guthrie County, IAIA10,78218–

79Monroe County, IAIA7,40617–

80Franklin County, IAIA9,86817–

81Keokuk County, IAIA9,79717–

82Calhoun County, IAIA9,56217–

83Sac County, IAIA9,52517–

84Palo Alto County, IAIA8,89916–

85Ida County, IAIA6,77716–

86Greene County, IAIA8,65815–

87Osceola County, IAIA5,98015–

88Kossuth County, IAIA14,32215–

89Van Buren County, IAIA7,13115–

90Decatur County, IAIA7,65514–

91Adair County, IAIA7,40313–

92Wayne County, IAIA6,73813–

93Fremont County, IAIA6,52213–

94Audubon County, IAIA5,50912–

95Monona County, IAIA8,53912–

96Pocahontas County, IAIA6,81912–

97Taylor County, IAIA5,83511–

98Ringgold County, IAIA4,6429–

99Adams County, IAIA3,6179–

SHOWING 1–99 OF 99

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UPDATED 2026-07-15 · DATA: US CENSUS BUREAU POPULATION ESTIMATES