Cleveland County was formed on 17 April 1873 and was named for Grover Cleveland, President of the United States. The county was originally named Dorsey County after Stephen W. Dorsey, a United States Senator from Arkansas but was changed in 1885.
According to the U.S. Census Bureau, the county has a total area of 1,551 km² (599 mi²). 1,548 km² (598 mi²) of it is land and 3 km² (1 mi²) of it is water. The total area is 0.18% water.
As of the census2 of 2000, there are 8,571 people, 3,273 households, and 2,513 families residing in the county. The population density is 6/km² (14/mi²). There are 3,834 housing units at an average density of 2/km² (6/mi²). The racial makeup of the county is 84.79% White, 13.22% Black or African American, 0.32% Native American, 0.14% Asian, 0.04% Pacific Islander, 0.68% from other races, and 0.83% from two or more races. 1.62% of the population are Hispanic or Latino of any race.
There are 3,273 households out of which 34.90% have children under the age of 18 living with them, 62.70% are married couples living together, 9.90% have a female householder with no husband present, and 23.20% are non-families. 21.40% of all households are made up of individuals and 10.00% have someone living alone who is 65 years of age or older. The average household size is 2.60 and the average family size is 3.00.
In the county the population is spread out with 26.20% under the age of 18, 7.90% from 18 to 24, 27.70% from 25 to 44, 24.70% from 45 to 64, and 13.60% who are 65 years of age or older. The median age is 37 years. For every 100 females there are 95.40 males. For every 100 females age 18 and over, there are 93.20 males.
The median income for a household in the county is $32,405, and the median income for a family is $38,164. Males have a median income of $31,282 versus $21,172 for females. The per capita income for the county is $15,362. 15.20% of the population and 11.40% of families are below the poverty line. Out of the total people living in poverty, 21.50% are under the age of 18 and 15.70% are 65 or older.