• county
  • FIPS 20087
  • Largest town: Oskaloosa

Jefferson County, Kansas

Jefferson County had 18,332 residents in the Census Vintage 2024 estimate, on 532.6 square miles of land. It ranks 30th of 105 in Kansas by population and 96th by land area.

Population
18,332
#30 of 105 in Kansas · #1,915 in US
Area
532.6 sq mi
#96 of 105 in Kansas · #1,959 in US
Density
34 / sq mi
#19 of 105 in Kansas · #1,807 in US
Median household income
$81,301
#5 of 105 in Kansas · #435 in US

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

Jefferson County within Kansas. Pin: Topeka.

Measure from here

Tools and pages that start from Jefferson County

Jefferson County population, land area and income

Jefferson County had 18,332 residents in the Census Vintage 2024 estimate, on 532.6 square miles of land. It ranks 30th of 105 in Kansas by population and 96th by land area. That works out to 34.4 people per square mile, below the US average of 96.3, and below the national county median.

The median county-equivalent in Kansas has 6,946 residents, so Jefferson County is 2.6 times that size.

Its SAIPE 2023 median household income of $81,301 is in the top quarter among 3,143 counties with an estimate.

National rank among 3,144

Population

18,332

3144th1st

1915th of 3,144 (US)

Land area

533 sq mi

3144th1st

1959th of 3,144 (US)

Density

34.4 / sq mi

3144th1st

1807th of 3,144 (US)

Median household income

$81,301

3143rd1st

435th of 3,143 (US)

Rank within Kansas (105)

Population

18,332

105th1st

30th of 105 (KS)

Land area

533 sq mi

105th1st

96th of 105 (KS)

Density

34.4 / sq mi

105th1st

19th of 105 (KS)

Median household income

$81,301

105th1st

5th of 105 (KS)

How Jefferson County's population changed since 2020

Jefferson County gained 7 residents between the July 2020 and July 2024 estimates, a rise of 0.0%. That ranks 31st of 105 in Kansas for growth. The median Kansas county changed by -1.0%, and the state as a whole by +1.1%.

Since the April 2020 estimates base, Jefferson County recorded 761 births and 953 deaths, a natural change of -192. Net international migration added +31 and net domestic migration, people moving to or from other US counties, came to +140. The largest single component was natural change, which removed 192 people.

18.3k202018.4k202118.3k202218.3k202318.3k2024
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
761
Deaths
953
Net international migration
+31
Net domestic migration
+140
Change, July 2023 to July 2024
+25

Where Jefferson County is

The Census internal point of Jefferson County is at 39.239600, -95.375300. It sits in UTM zone 15N. The map shades Kansas's 105 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.

Harper County: -1.0%Phillips County: -4.6%Seward County: -2.7%Grant County: -3.1%Pawnee County: -3.8%Haskell County: -4.5%Ness County: -2.3%Logan County: -1.8%Wichita County: -3.6%Greenwood County: -1.7%Stanton County: -0.7%Edwards County: -5.3%Gray County: +1.6%Franklin County: +1.0%Saline County: -1.5%Allen County: -0.9%Lyon County: +1.3%Cloud County: -3.3%Brown County: -3.6%Rice County: -1.1%Lincoln County: -0.6%Osborne County: -4.0%Rooks County: -2.8%Russell County: -0.8%Jefferson County: +0.0%Jewell County: -1.0%Lane County: -5.6%Sheridan County: -1.9%Gove County: -2.1%Trego County: -1.1%Montgomery County: -3.0%Sumner County: +0.1%Graham County: -1.5%Marion County: -1.0%Washington County: +0.8%Stevens County: -4.0%Kiowa County: -0.7%Mitchell County: +0.4%Cheyenne County: +1.3%Ellis County: +0.2%Rush County: -4.6%Scott County: -4.3%Comanche County: +0.7%Wallace County: -2.6%Nemaha County: -2.0%Linn County: +2.6%Ford County: -0.4%Dickinson County: +1.4%Ellsworth County: -0.9%Labette County: -2.3%Cowley County: -1.0%Neosho County: -2.2%Wilson County: -2.2%Thomas County: -1.7%Greeley County: -9.6%Osage County: -0.0%Finney County: +0.1%Kearny County: -3.8%Kingman County: -6.4%Republic County: -1.3%Ottawa County: +2.1%Smith County: -0.5%Crawford County: -0.1%Elk County: -1.5%Miami County: +4.4%Hodgeman County: -3.7%Morris County: -1.7%Morton County: -8.1%Harvey County: -1.0%Meade County: -4.2%Sedgwick County: +2.1%Geary County: -3.6%Woodson County: +0.4%Bourbon County: +0.6%Chase County: -2.6%Pratt County: -0.0%Reno County: -0.8%Chautauqua County: -1.2%Norton County: -2.1%Marshall County: -0.7%Doniphan County: +1.4%Cherokee County: -0.9%Barton County: -2.3%Riley County: +0.8%Butler County: +2.6%Stafford County: -3.7%Anderson County: +0.9%Sherman County: -1.8%Rawlins County: -5.5%Pottawatomie County: +5.7%McPherson County: +0.5%Coffey County: -0.7%Hamilton County: +0.0%Atchison County: -0.5%Shawnee County: -0.4%Leavenworth County: +3.3%Jackson County: +2.2%Clark County: -5.3%Douglas County: +2.7%Clay County: -1.9%Barber County: -3.2%Johnson County: +3.5%Wabaunsee County: +3.2%Decatur County: -1.1%Wyandotte County: +0.3%
Change 2020 to 2024
  1. < -3.6%
  2. < -1.7%
  3. < -0.7%
  4. < +0.6%
  5. ≥ +0.6%
no data

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

Internal point

Decimal
39.239600, -95.375300
DMS
39°14'22.56"N 95°22'31.08"W
UTM
15N 295002.2E 4346054.6N
Geohash
9yupjxmg4
Plus code
86F66JQF+RV

Towns in Jefferson County

2 incorporated places of 1,000+ people have residents in Jefferson County, 2,139 people together, or 12% 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 Oskaloosa with 1,073.

  1. 01Oskaloosa1,073
  2. 02Valley Falls1,066
Census Vintage 2024 subcounty estimates, county parts of incorporated places (SUMLEV 157).

Counties bordering Jefferson County

The Census 2024 county adjacency file lists 5 neighbors for Jefferson County. The most populous is Shawnee County, KS, with 177,942 residents. Distances run between Census internal points in a straight line.

Distance to Topeka and the nearest big city

Topeka is 21.0 miles SW of Jefferson County's internal point in a straight line. The nearest place of 100,000 or more is Topeka, KS (population 125,467), 22.2 miles away. The nearest place of 10,000 or more is Lawrence, KS (population 97,271), 20.2 miles away.

Jefferson County FIPS code

The FIPS code of Jefferson County is 20087: state code 20 for Kansas plus county code 087. Use it as text, with the leading zero, when joining Census, BLS, or CDC county tables. SAIPE lists its 2023 median household income as $81,301.

Questions people ask

What is the population of Jefferson County, Kansas?

The Census Vintage 2024 estimate for July 1, 2024 is 18,332. That is up 7 people (0.0%) from the July 2020 estimate of 18,325.

What is the FIPS code of Jefferson County?

20087. The first two digits (20) are Kansas; the last three (087) identify the county.

What is the largest town in Jefferson County?

Oskaloosa, with 1,073 residents inside Jefferson County in 2024.

Which counties border Jefferson County?

5 county-equivalents border it in the Census 2024 adjacency file: Shawnee County, KS; Douglas County, KS; Leavenworth County, KS; Atchison County, KS; Jackson County, KS.

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.