| Rank |
County |
Population (2012) |
| 1 |
St Louis County, Missouri
|
1,000,438
|
| 2 |
Jackson County, Missouri
|
677,377
|
| 3 |
St Charles County, Missouri
|
368,666
|
| 4 |
St Louis city, Missouri
|
318,172
|
| 5 |
Greene County, Missouri
|
280,626
|
| 6 |
Clay County, Missouri
|
227,577
|
| 7 |
Jefferson County, Missouri
|
220,209
|
| 8 |
Boone County, Missouri
|
168,535
|
| 9 |
Jasper County, Missouri
|
115,258
|
| 10 |
Franklin County, Missouri
|
101,412
|
| 11 |
Cass County, Missouri
|
100,376
|
| 12 |
Platte County, Missouri
|
92,054
|
| 13 |
Buchanan County, Missouri
|
89,706
|
| 14 |
Christian County, Missouri
|
79,824
|
| 15 |
Cape Girardeau County, Missouri
|
76,950
|
| 16 |
Cole County, Missouri
|
76,363
|
| 17 |
St Francois County, Missouri
|
65,917
|
| 18 |
Newton County, Missouri
|
59,069
|
| 19 |
Johnson County, Missouri
|
54,397
|
| 20 |
Lincoln County, Missouri
|
53,354
|
| 21 |
Pulaski County, Missouri
|
53,259
|
| 22 |
Taney County, Missouri
|
52,956
|
| 23 |
Phelps County, Missouri
|
44,987
|
| 24 |
Callaway County, Missouri
|
44,305
|
| 25 |
Camden County, Missouri
|
43,845
|
| 26 |
Butler County, Missouri
|
43,053
|
| 27 |
Pettis County, Missouri
|
42,319
|
| 28 |
Howell County, Missouri
|
40,629
|
| 29 |
Scott County, Missouri
|
39,139
|
| 30 |
Lawrence County, Missouri
|
38,467
|
| 31 |
Webster County, Missouri
|
36,351
|
| 32 |
Barry County, Missouri
|
35,546
|
| 33 |
Laclede County, Missouri
|
35,417
|
| 34 |
Lafayette County, Missouri
|
33,080
|
| 35 |
Warren County, Missouri
|
32,753
|
| 36 |
Dunklin County, Missouri
|
31,826
|
| 37 |
Stone County, Missouri
|
31,568
|
| 38 |
Polk County, Missouri
|
31,017
|
| 39 |
Stoddard County, Missouri
|
29,795
|
| 40 |
Marion County, Missouri
|
28,745
|
| 41 |
Texas County, Missouri
|
25,810
|
| 42 |
Audrain County, Missouri
|
25,621
|
| 43 |
Adair County, Missouri
|
25,581
|
| 44 |
Randolph County, Missouri
|
25,330
|
| 45 |
Washington County, Missouri
|
25,095
|
| 46 |
Crawford County, Missouri
|
24,832
|
| 47 |
Miller County, Missouri
|
24,817
|
| 48 |
Nodaway County, Missouri
|
23,419
|
| 49 |
Saline County, Missouri
|
23,339
|
| 50 |
Ray County, Missouri
|
23,064
|
| 51 |
McDonald County, Missouri
|
22,876
|
| 52 |
Henry County, Missouri
|
22,153
|
| 53 |
Vernon County, Missouri
|
20,748
|
| 54 |
Clinton County, Missouri
|
20,508
|
| 55 |
Morgan County, Missouri
|
20,117
|
| 56 |
Perry County, Missouri
|
19,018
|
| 57 |
Benton County, Missouri
|
18,962
|
| 58 |
Wright County, Missouri
|
18,629
|
| 59 |
Pike County, Missouri
|
18,565
|
| 60 |
New Madrid County, Missouri
|
18,488
|
| 61 |
Pemiscot County, Missouri
|
18,111
|
| 62 |
Ste Genevieve County, Missouri
|
17,740
|
| 63 |
Cooper County, Missouri
|
17,520
|
| 64 |
Andrew County, Missouri
|
17,417
|
| 65 |
Dallas County, Missouri
|
16,799
|
| 66 |
Bates County, Missouri
|
16,709
|
| 67 |
Dent County, Missouri
|
15,647
|
| 68 |
Moniteau County, Missouri
|
15,625
|
| 69 |
Macon County, Missouri
|
15,573
|
| 70 |
Livingston County, Missouri
|
15,037
|
| 71 |
Gasconade County, Missouri
|
14,972
|
| 72 |
Mississippi County, Missouri
|
14,322
|
| 73 |
Ripley County, Missouri
|
14,036
|
| 74 |
Osage County, Missouri
|
13,858
|
| 75 |
Cedar County, Missouri
|
13,799
|
| 76 |
Douglas County, Missouri
|
13,585
|
| 77 |
Wayne County, Missouri
|
13,402
|
| 78 |
DeKalb County, Missouri
|
12,940
|
| 79 |
Linn County, Missouri
|
12,484
|
| 80 |
Madison County, Missouri
|
12,448
|
| 81 |
Bollinger County, Missouri
|
12,382
|
| 82 |
Barton County, Missouri
|
12,337
|
| 83 |
Montgomery County, Missouri
|
11,996
|
| 84 |
Oregon County, Missouri
|
10,997
|
| 85 |
Iron County, Missouri
|
10,374
|
| 86 |
Grundy County, Missouri
|
10,338
|
| 87 |
Ralls County, Missouri
|
10,277
|
| 88 |
Lewis County, Missouri
|
10,174
|
| 89 |
Howard County, Missouri
|
10,169
|
| 90 |
Ozark County, Missouri
|
9,601
|
| 91 |
St Clair County, Missouri
|
9,474
|
| 92 |
Hickory County, Missouri
|
9,391
|
| 93 |
Caldwell County, Missouri
|
9,145
|
| 94 |
Carroll County, Missouri
|
9,086
|
| 95 |
Maries County, Missouri
|
9,014
|
| 96 |
Harrison County, Missouri
|
8,728
|
| 97 |
Monroe County, Missouri
|
8,703
|
| 98 |
Shannon County, Missouri
|
8,318
|
| 99 |
Daviess County, Missouri
|
8,239
|
| 100 |
Chariton County, Missouri
|
7,649
|
| 101 |
Dade County, Missouri
|
7,568
|
| 102 |
Clark County, Missouri
|
6,969
|
| 103 |
Gentry County, Missouri
|
6,777
|
| 104 |
Reynolds County, Missouri
|
6,667
|
| 105 |
Sullivan County, Missouri
|
6,546
|
| 106 |
Carter County, Missouri
|
6,262
|
| 107 |
Shelby County, Missouri
|
6,234
|
| 108 |
Atchison County, Missouri
|
5,517
|
| 109 |
Putnam County, Missouri
|
4,931
|
| 110 |
Scotland County, Missouri
|
4,877
|
| 111 |
Holt County, Missouri
|
4,655
|
| 112 |
Schuyler County, Missouri
|
4,370
|
| 113 |
Knox County, Missouri
|
4,082
|
| 114 |
Mercer County, Missouri
|
3,729
|
| 115 |
Worth County, Missouri
|
2,079
|