Jefferson County is included in the
Topeka, Kansas metropolitan area.
2020 census As of the
2020 census, the county had a population of 18,368, a median age of 43.7 years, 23.4% of residents under the age of 18, and 19.8% of residents 65 years of age or older. For every 100 females there were 102.2 males and for every 100 females age 18 and over there were 101.2 males age 18 and over. The racial makeup of the county was 91.4% White, 0.6%
Black or African American, 0.7%
American Indian and Alaska Native, 0.2%
Asian, 0.2%
Native Hawaiian and
Pacific Islander, 0.7% from some other race, and 6.2% from
two or more races.
Hispanic or Latino residents of any race comprised 3.1% of the population. There were 7,209 households in the county, of which 30.0% had children under the age of 18 living with them and 18.3% had a female householder with no spouse or partner present. About 23.3% of all households were made up of individuals and 11.4% had someone living alone who was 65 years of age or older. there were 18,426 people, 6,830 households and 5,190 families residing in the county. The population density was . There were 7,491 housing units at an average density of . The
racial makeup of the county was 96.70%
White, 0.92%
Native American, 0.37%
Black or
African American, 0.17%
Asian, 0.01%
Pacific Islander, 0.42% from other races, and 1.41% from
two or more races.
Hispanic or
Latino of any race were 1.28% of the population. There were 6,830
households, of which 35.70% had children under the age of 18 living with them, 65.20% were
married couples living together, 7.00% had a female householder with no husband present, and 24.00% were non-families. 20.10% of all households were made up of individuals, and 9.30% had someone living alone who was 65 years of age or older. The average household size was 2.66 and the average family size was 3.07. 27.40% of the population were under the age of 18, 7.00% from 18 to 24, 28.00% from 25 to 44, 24.90% from 45 to 64, and 12.80% who were 65 years of age or older. The median age was 38 years. For every 100 females, there were 102.60 males. For every 100 females age 18 and over, there were 98.90 males. The
median household income was $45,535 and the median family income was $50,557. Males had a median income of $36,174 compared with $25,468 for females. The
per capita income for the county was $19,373. About 5.30% of families and 6.70% of the population were below the
poverty line, including 6.90% of those under age 18 and 7.70% of those age 65 or over. ==Government==