Jewell County (county code JW) is a county located in the U.S. state of Kansas. As of the 2010 census, the county population was 3,077 with a 2018 estimate of 2,841. Its county seat and most populous city is Mankato.
According to the U.S. Census Bureau, the county has a total area of 914 square miles (2,370 km), of which 910 square miles (2,400 km) is land and 4.6 square miles (12 km) (0.5%) is water.
As of the 2000 census, there were 3,791 people, 1,695 households, and 1,098 families residing in the county. The population density was 4 people per square mile (2/km²). There were 2,103 housing units at an average density of 2 per square mile (1/km²). The racial makeup of the county was 98.79% White, 0.34% Native American, 0.05% Asian, 0.03% Black or African American, 0.03% Pacific Islander, 0.05% from other races, and 0.71% from two or more races. Hispanic or Latino of any race were 0.71% of the population.
There were 1,695 households out of which 23.70% had children under the age of 18 living with them, 58.10% were married couples living together, 4.80% had a female householder with no husband present, and 35.20% were non-families. 32.40% of all households were made up of individuals and 18.10% had someone living alone who was 65 years of age or older. The average household size was 2.21 and the average family size was 2.80.
In the county, the population was spread out with 21.90% under the age of 18, 4.40% from 18 to 24, 21.50% from 25 to 44, 26.20% from 45 to 64, and 25.90% who were 65 years of age or older. The median age was 46 years. For every 100 females there were 97.90 males. For every 100 females age 18 and over, there were 96.00 males.
The median income for a household in the county was $30,538, and the median income for a family was $36,953. Males had a median income of $24,821 versus $18,170 for females. The per capita income for the county was $16,644. About 8.40% of families and 11.60% of the population were below the poverty line, including 12.80% of those under age 18 and 10.90% of those age 65 or over.