Olney (/ˈɔːlni/ AWL-nee) is a city in Richland County, Illinois, United States. The population was 8,631 at the 2000 census. It is the county seat of Richland County.
Olney is located at 38°44′N 88°5′W / 38.733°N 88.083°W / 38.733; -88.083 (38.7306, -88.0819).
According to the 2010 census, Olney has a total area of 6.664 square miles (17.26 km), of which 6.66 square miles (17.25 km) (or 99.94%) is land and 0.004 square miles (0.01 km) (or 0.06%) is water.
As of the census of 2000, there were 8,631 people, 3,755 households, and 2,301 families residing in the city. The population density was 1,498.4 people per square mile (578.5/km²). There were 4,283 housing units at an average density of 743.5 per square mile (287.1/km²). The racial makeup of the city was 97.67% White, 0.48% African American, 0.16% Native American, 0.64% Asian, 0.03% Pacific Islander, 0.32% from other races, and 0.70% from two or more races. Hispanic or Latino of any race were 0.96% of the population.
There were 3,755 households out of which 28.2% had children under the age of 18 living with them, 47.4% were married couples living together, 10.6% had a female householder with no husband present, and 38.7% were non-families. 33.7% of all households were made up of individuals and 17.3% had someone living alone who was 65 years of age or older. The average household size was 2.26 and the average family size was 2.89.
In the city, the population was spread out with 23.8% under the age of 18, 9.1% from 18 to 24, 25.6% from 25 to 44, 21.0% from 45 to 64, and 20.5% who were 65 years of age or older. The median age was 39 years. For every 100 females, there were 86.9 males. For every 100 females age 18 and over, there were 82.4 males.
The median income for a household in the city was $28,084 and the median income for a family was $37,365. Males had a median income of $29,547 versus $18,440 for females. The per capita income for the city was $16,218. About 13.0% of families and 17.0% of the population were below the poverty line, including 21.9% of those under age 18 and 8.0% of those age 65 or over.