Douglas County (county code DG) is a county located in the U.S. state of Kansas and is included in the Kansas City-Overland Park-Kansas City MO-KS Combined statistical area. As of the 2010 census, the county population was 110,826, making it the fifth-most populous county in Kansas. Its county seat and most populous city is Lawrence, which is home to the University of Kansas main campus.
According to the U.S. Census Bureau, the county has a total area of 475 square miles (1,230 km), of which 456 square miles (1,180 km) is land and 19 square miles (49 km) (4.0%) is water. It is the fifth-smallest county in Kansas by land area. Much of its northern boundary is defined by the Kansas River, which flows through Lawrence and provides hydropower at the Bowersock Dam.
Douglas County comprises the Lawrence, KS Metropolitan Statistical Area, which is also included in the Kansas City-Overland Park-Kansas City, MO-KS Combined Statistical Area.
As of the 2000 census, there were 99,962 people, 38,486 households, and 21,167 families residing in the county. The population density was 219 people per square mile (84/km²). There were 40,250 housing units at an average density of 88 per square mile (34/km²). The racial makeup of the county was 86.1% White, 4.2% Black or African American, 2.6% Native American, 3.1% Asian, 0.1% Pacific Islander, 1.2% from other races, and 2.7% from two or more races. Hispanic or Latino of any race were 3.3% of the population.
There were 38,486 households out of which 27.4% had children under the age of 18 living with them, 43.1% were married couples living together, 8.5% had a female householder with no husband present, and 45.0% were non-families. 28.5% of all households were made up of individuals and 5.8% had someone living alone who was 65 years of age or older. The average household size was 2.37 and the average family size was 2.97.
In the county, the population was spread out with 20.4% under the age of 18, 26.4% from 18 to 24, 28.3% from 25 to 44, 16.9% from 45 to 64, and 7.9% who were 65 years of age or older. The median age was 27 years. For every 100 females there were 98.70 males. For every 100 females age 18 and over, there were 97.70 males.
The median income for a household in the county was $37,547, and the median income for a family was $53,991. Males had a median income of $35,577 versus $27,225 for females. The per capita income for the county was $19,952. About 6.2% of families and 15.9% of the population were below the poverty line, including 9.0% of those under age 18 and 7.3% of those age 65 or over.