| Rank |
County |
Population (2012) |
| 1 |
Jefferson County, Kentucky
|
750,828
|
| 2 |
Fayette County, Kentucky
|
305,489
|
| 3 |
Kenton County, Kentucky
|
161,711
|
| 4 |
Boone County, Kentucky
|
123,316
|
| 5 |
Warren County, Kentucky
|
117,110
|
| 6 |
Hardin County, Kentucky
|
107,025
|
| 7 |
Daviess County, Kentucky
|
97,847
|
| 8 |
Campbell County, Kentucky
|
90,908
|
| 9 |
Madison County, Kentucky
|
84,786
|
| 10 |
Bullitt County, Kentucky
|
75,896
|
| 11 |
Christian County, Kentucky
|
75,427
|
| 12 |
McCracken County, Kentucky
|
65,549
|
| 13 |
Pike County, Kentucky
|
64,178
|
| 14 |
Pulaski County, Kentucky
|
63,593
|
| 15 |
Oldham County, Kentucky
|
61,412
|
| 16 |
Laurel County, Kentucky
|
59,462
|
| 17 |
Franklin County, Kentucky
|
49,804
|
| 18 |
Jessamine County, Kentucky
|
49,635
|
| 19 |
Boyd County, Kentucky
|
49,164
|
| 20 |
Scott County, Kentucky
|
49,057
|
| 21 |
Hopkins County, Kentucky
|
46,718
|
| 22 |
Henderson County, Kentucky
|
46,513
|
| 23 |
Nelson County, Kentucky
|
44,319
|
| 24 |
Shelby County, Kentucky
|
43,614
|
| 25 |
Barren County, Kentucky
|
42,631
|
| 26 |
Floyd County, Kentucky
|
38,949
|
| 27 |
Calloway County, Kentucky
|
37,655
|
| 28 |
Graves County, Kentucky
|
37,544
|
| 29 |
Greenup County, Kentucky
|
36,707
|
| 30 |
Clark County, Kentucky
|
35,787
|
| 31 |
Whitley County, Kentucky
|
35,499
|
| 32 |
Knox County, Kentucky
|
31,735
|
| 33 |
Marshall County, Kentucky
|
31,344
|
| 34 |
Muhlenberg County, Kentucky
|
31,181
|
| 35 |
Meade County, Kentucky
|
29,237
|
| 36 |
Boyle County, Kentucky
|
28,658
|
| 37 |
Harlan County, Kentucky
|
28,543
|
| 38 |
Perry County, Kentucky
|
28,241
|
| 39 |
Bell County, Kentucky
|
28,183
|
| 40 |
Carter County, Kentucky
|
27,348
|
| 41 |
Montgomery County, Kentucky
|
26,902
|
| 42 |
Logan County, Kentucky
|
26,646
|
| 43 |
Grayson County, Kentucky
|
25,964
|
| 44 |
Woodford County, Kentucky
|
25,077
|
| 45 |
Taylor County, Kentucky
|
24,691
|
| 46 |
Grant County, Kentucky
|
24,485
|
| 47 |
Lincoln County, Kentucky
|
24,461
|
| 48 |
Ohio County, Kentucky
|
24,075
|
| 49 |
Letcher County, Kentucky
|
23,952
|
| 50 |
Rowan County, Kentucky
|
23,447
|
| 51 |
Johnson County, Kentucky
|
23,383
|
| 52 |
Anderson County, Kentucky
|
21,728
|
| 53 |
Clay County, Kentucky
|
21,556
|
| 54 |
Mercer County, Kentucky
|
21,261
|
| 55 |
Wayne County, Kentucky
|
20,824
|
| 56 |
Allen County, Kentucky
|
20,210
|
| 57 |
Marion County, Kentucky
|
20,090
|
| 58 |
Breckinridge County, Kentucky
|
20,071
|
| 59 |
Bourbon County, Kentucky
|
19,978
|
| 60 |
Adair County, Kentucky
|
18,675
|
| 61 |
Harrison County, Kentucky
|
18,624
|
| 62 |
Hart County, Kentucky
|
18,366
|
| 63 |
McCreary County, Kentucky
|
18,069
|
| 64 |
Simpson County, Kentucky
|
17,538
|
| 65 |
Mason County, Kentucky
|
17,512
|
| 66 |
Russell County, Kentucky
|
17,497
|
| 67 |
Spencer County, Kentucky
|
17,416
|
| 68 |
Rockcastle County, Kentucky
|
17,006
|
| 69 |
Garrard County, Kentucky
|
16,913
|
| 70 |
Knott County, Kentucky
|
16,124
|
| 71 |
Casey County, Kentucky
|
16,082
|
| 72 |
Lawrence County, Kentucky
|
15,848
|
| 73 |
Henry County, Kentucky
|
15,318
|
| 74 |
Union County, Kentucky
|
14,850
|
| 75 |
Pendleton County, Kentucky
|
14,604
|
| 76 |
Fleming County, Kentucky
|
14,560
|
| 77 |
Estill County, Kentucky
|
14,493
|
| 78 |
Trigg County, Kentucky
|
14,447
|
| 79 |
Larue County, Kentucky
|
14,151
|
| 80 |
Lewis County, Kentucky
|
13,835
|
| 81 |
Morgan County, Kentucky
|
13,668
|
| 82 |
Breathitt County, Kentucky
|
13,635
|
| 83 |
Webster County, Kentucky
|
13,583
|
| 84 |
Jackson County, Kentucky
|
13,331
|
| 85 |
Magoffin County, Kentucky
|
13,041
|
| 86 |
Caldwell County, Kentucky
|
12,935
|
| 87 |
Butler County, Kentucky
|
12,840
|
| 88 |
Martin County, Kentucky
|
12,743
|
| 89 |
Todd County, Kentucky
|
12,651
|
| 90 |
Powell County, Kentucky
|
12,483
|
| 91 |
Edmonson County, Kentucky
|
12,071
|
| 92 |
Washington County, Kentucky
|
11,833
|
| 93 |
Bath County, Kentucky
|
11,802
|
| 94 |
Green County, Kentucky
|
11,315
|
| 95 |
Leslie County, Kentucky
|
11,170
|
| 96 |
Carroll County, Kentucky
|
10,900
|
| 97 |
Monroe County, Kentucky
|
10,821
|
| 98 |
Owen County, Kentucky
|
10,765
|
| 99 |
Clinton County, Kentucky
|
10,285
|
| 100 |
Metcalfe County, Kentucky
|
9,969
|
| 101 |
McLean County, Kentucky
|
9,506
|
| 102 |
Livingston County, Kentucky
|
9,423
|
| 103 |
Crittenden County, Kentucky
|
9,280
|
| 104 |
Trimble County, Kentucky
|
8,787
|
| 105 |
Hancock County, Kentucky
|
8,677
|
| 106 |
Bracken County, Kentucky
|
8,494
|
| 107 |
Gallatin County, Kentucky
|
8,479
|
| 108 |
Lyon County, Kentucky
|
8,351
|
| 109 |
Ballard County, Kentucky
|
8,333
|
| 110 |
Elliott County, Kentucky
|
7,780
|
| 111 |
Lee County, Kentucky
|
7,706
|
| 112 |
Wolfe County, Kentucky
|
7,164
|
| 113 |
Nicholas County, Kentucky
|
7,000
|
| 114 |
Cumberland County, Kentucky
|
6,819
|
| 115 |
Fulton County, Kentucky
|
6,525
|
| 116 |
Menifee County, Kentucky
|
6,220
|
| 117 |
Carlisle County, Kentucky
|
5,034
|
| 118 |
Hickman County, Kentucky
|
4,754
|
| 119 |
Owsley County, Kentucky
|
4,722
|
| 120 |
Robertson County, Kentucky
|
2,188
|