Carbondale is a city in Southern Illinois in the midwest United States, about one hour north of Cairo. It is known mainly as the site of the main campus of Southern Illinois University. The city is located in Jackson County, Illinois. As of the 2000 census, the city had a total population of 20,681.

As of the censusGR2 of 2000, there are 20,681 people, 9,981 households, and 3,493 families residing in the city. The population density is 671.6/km˛ (1,738.7/mi˛). There are 10,968 housing units at an average density of 356.2/km˛ (922.1/mi˛). The racial makeup of the city is 66.08% White, 23.14% Black or African American, 0.22% Native American, 6.67% Asian, 0.08% Pacific Islander, 1.42% from other races, and 2.40% from two or more races. 3.05% of the population are Hispanic or Latino of any race. There are 9,981 households out of which 17.0% have children under the age of 18 living with them, 22.1% are married couples living together, 10.1% have a female householder with no husband present, and 65.0% are non-families. 43.5% of all households are made up of individuals and 6.9% have someone living alone who is 65 years of age or older. The average household size is 1.99 and the average family size is 2.78.