• county
  • FIPS 21111
  • Largest town: Louisville/Jefferson County

Jefferson County, Kentucky

Jefferson County had 793,881 residents in the Census Vintage 2024 estimate, on 380.8 square miles of land. It is the most populous of Kentucky's 120 county-equivalents.

Population
793,881
#1 of 120 in Kentucky · #83 in US
Area
380.8 sq mi
#38 of 120 in Kentucky · #2,600 in US
Density
2,085 / sq mi
#1 of 120 in Kentucky · #68 in US
Median household income
$64,977
#28 of 120 in Kentucky · #1,375 in US

Census Vintage 2024 estimates · SAIPE 2023 income · 2024 Gazetteer land area

Jefferson County within Kentucky. Pin: Frankfort.

Measure from here

Tools and pages that start from Jefferson County

Jefferson County population, land area and income

Jefferson County had 793,881 residents in the Census Vintage 2024 estimate, on 380.8 square miles of land. It is the most populous of Kentucky's 120 county-equivalents. That works out to 2,084.6 people per square mile, 21.7 times the US average of 96.3, and in the top tenth nationally.

The median county-equivalent in Kentucky has 19,740 residents, so Jefferson County is 40.2 times that size.

Its SAIPE 2023 median household income of $64,977 is above the national county median among 3,143 counties with an estimate.

National rank among 3,144

Population

793,881

3144th1st

83rd of 3,144 (US)

Land area

381 sq mi

3144th1st

2600th of 3,144 (US)

Density

2,084.6 / sq mi

3144th1st

68th of 3,144 (US)

Median household income

$64,977

3143rd1st

1375th of 3,143 (US)

Rank within Kentucky (120)

Population

793,881

120th1st

1st of 120 (KY)

Land area

381 sq mi

120th1st

38th of 120 (KY)

Density

2,084.6 / sq mi

120th1st

1st of 120 (KY)

Median household income

$64,977

120th1st

28th of 120 (KY)

How Jefferson County's population changed since 2020

Jefferson County gained 10,985 residents between the July 2020 and July 2024 estimates, a rise of 1.4%. That ranks 59th of 120 in Kentucky for growth. The median Kentucky county changed by +1.4%, and the state as a whole by +1.8%.

Since the April 2020 estimates base, Jefferson County recorded 40,265 births and 38,799 deaths, a natural change of +1,466. Net international migration added +30,887 and net domestic migration, people moving to or from other US counties, came to -21,615. The largest single component was international migration, which added 30,887 people.

782.9k2020777.6k2021777.3k2022783.4k2023793.9k2024
Census Vintage 2024 county estimates for July 1 of each year. The axis starts above zero so year-to-year changes are visible.

Components of change, April 2020 to July 2024

Births
40,265
Deaths
38,799
Net international migration
+30,887
Net domestic migration
-21,615
Change, July 2023 to July 2024
+10,500

Where Jefferson County is

The Census internal point of Jefferson County is at 38.189500, -85.657600. It sits in UTM zone 16N. The map shades Kentucky's 120 county-equivalents by population change from 2020 to 2024, darker for faster growth, with Jefferson County outlined. Dots are towns of 1,000+ people with residents in it.

Adair County: +1.9%Kenton County: +3.3%Owen County: +1.2%Morgan County: +4.1%Bracken County: +1.1%Edmonson County: +4.0%Trigg County: +3.4%Jackson County: +3.0%Spencer County: +6.8%Clark County: +1.7%Jessamine County: +6.6%Green County: +3.8%Henry County: +3.2%Graves County: +0.8%Webster County: -1.3%Washington County: +1.9%Ohio County: +0.8%Knott County: -5.1%Meade County: +1.4%Carroll County: +2.5%Scott County: +7.2%Lincoln County: +2.7%Greenup County: -1.7%Boyle County: +2.1%Hardin County: +1.8%Nelson County: +4.1%Hart County: +3.2%Christian County: -2.4%Carlisle County: -0.6%Crittenden County: -0.2%Elliott County: -1.0%Garrard County: +6.3%Larue County: +1.7%Lee County: -0.7%Leslie County: -7.1%Hancock County: -1.0%Lewis County: -1.6%Lyon County: +4.6%McLean County: -0.1%Magoffin County: -4.2%Martin County: -4.9%Mason County: -1.1%Rockcastle County: +1.0%Menifee County: +3.2%Russell County: +2.6%Whitley County: +1.5%Todd County: +3.9%Union County: -3.5%Wolfe County: -2.9%Bell County: -3.9%Boyd County: -0.9%Butler County: +1.9%Metcalfe County: +2.7%Grant County: +2.8%Simpson County: +3.7%Pike County: -5.2%Gallatin County: +1.5%Harlan County: -6.4%Fayette County: +2.1%Logan County: +3.5%Muhlenberg County: -1.2%Bath County: +1.8%Mercer County: +3.8%Barren County: +2.5%Franklin County: +1.6%Bullitt County: +4.2%Boone County: +5.6%Campbell County: +0.9%Jefferson County: +1.4%Wayne County: +0.4%Ballard County: -1.1%Anderson County: +4.1%Pulaski County: +2.7%Knox County: -1.7%Laurel County: +1.0%Breckinridge County: +3.8%Oldham County: +4.2%Letcher County: -6.2%Lawrence County: -3.1%McCracken County: -0.6%Nicholas County: +3.7%Owsley County: -2.6%Powell County: -1.3%Bourbon County: +0.2%Calloway County: +3.7%Henderson County: -1.1%Clinton County: -0.5%Warren County: +9.6%Montgomery County: +2.4%Floyd County: -3.5%Woodford County: +3.1%Hopkins County: -0.3%Johnson County: -2.4%Marshall County: +0.1%Estill County: -1.1%Cumberland County: +3.2%Fleming County: +3.3%Madison County: +7.1%Carter County: -1.9%Allen County: +7.1%Daviess County: +1.0%Harrison County: +4.3%Perry County: -5.7%Fulton County: -3.5%Clay County: -3.5%Robertson County: +9.1%Trimble County: +1.5%Taylor County: +3.1%Shelby County: +3.9%McCreary County: -0.2%Breathitt County: -6.5%Livingston County: -0.6%Hickman County: -3.0%Rowan County: -0.2%Casey County: +0.2%Monroe County: -1.4%Marion County: +1.3%Grayson County: +2.3%Caldwell County: -0.2%Pendleton County: +1.3%
Change 2020 to 2024
  1. < -1.6%
  2. < +0.2%
  3. < +1.9%
  4. < +3.7%
  5. ≥ +3.7%
no data

Orange pin: Jefferson County internal point. Dark pin: Frankfort.

Internal point

Decimal
38.189500, -85.657600
DMS
38°11'22.20"N 85°39'27.36"W
UTM
16N 617557.8E 4227692.3N
Geohash
dng16b4jc
Plus code
86CP58QR+RX

Towns in Jefferson County

24 incorporated places of 1,000+ people have residents in Jefferson County, 765,728 people together, or 96% of the county. Each figure counts only the part of the town inside Jefferson County; towns marked "part" extend into another county. The largest is Louisville/Jefferson County with 640,796.

  1. 01Louisville/Jefferson County640,796
  2. 02Jeffersontown29,388
  3. 03St. Matthews17,806
  4. 04Shively15,850
  5. 05Lyndon11,221
  6. 06Middletown9,908
  7. 07Douglass Hills5,558
  8. 08Hurstbourne4,777
  9. 09Prospect (part)4,633
  10. 10Indian Hills2,934
  11. 11Graymoor-Devondale2,810
  12. 12Anchorage2,538
  13. 13Windy Hills2,471
  14. 14Hurstbourne Acres2,005
  15. 15Worthington Hills1,598
Census Vintage 2024 subcounty estimates, county parts of incorporated places (SUMLEV 157).

Counties bordering Jefferson County

The Census 2024 county adjacency file lists 8 neighbors for Jefferson County, including 3 across a state line. The most populous is Clark County, IN, with 127,479 residents. Distances run between Census internal points in a straight line.

Distance to Frankfort and the nearest big city

Frankfort is 42.5 miles E of Jefferson County's internal point in a straight line. The nearest place of 100,000 or more is Louisville/Jefferson County, KY (population 640,796), 1.7 miles away.

Jefferson County FIPS code

The FIPS code of Jefferson County is 21111: state code 21 for Kentucky plus county code 111. Use it as text, with the leading zero, when joining Census, BLS, or CDC county tables. SAIPE lists its 2023 median household income as $64,977.

Questions people ask

What is the population of Jefferson County, Kentucky?

The Census Vintage 2024 estimate for July 1, 2024 is 793,881. That is up 10,985 people (1.4%) from the July 2020 estimate of 782,896.

What is the FIPS code of Jefferson County?

21111. The first two digits (21) are Kentucky; the last three (111) identify the county.

What is the largest town in Jefferson County?

Louisville/Jefferson County, with 640,796 residents inside Jefferson County in 2024.

Which counties border Jefferson County?

8 county-equivalents border it in the Census 2024 adjacency file: Clark County, IN; Hardin County, KY; Bullitt County, KY; Floyd County, IN; Oldham County, KY; Shelby County, KY; Harrison County, IN; Spencer County, KY.

Sources and data as of

Data as of: Census Vintage 2024 population estimates, 2024 Gazetteer land area and internal points, SAIPE 2023 median household income.

  1. 01Census Vintage 2024 county population estimates
  2. 02Census 2024 Gazetteer, counties
  3. 03Census SAIPE 2023 state and county estimates
  4. 04Census Vintage 2024 subcounty population estimates
  5. 05Census 2024 county adjacency file
  6. 06Census 2024 cartographic boundary file, counties (1:5,000,000)

How every number is computed: methodology. Spotted a wrong figure? Report an error.