Adjacent counties

• Decatur County (south)
• Lucas County (east)
• Madison County (northwest)
• Union County (west)
• Warren County (northeast)

Highways

• Interstate 35 - runs north–south through central Clarke County, passing Osceola
• U.S. Highway 34 - runs east–west through central Clarke County, passing Osceola
• U.S. Highway 69 - enters northeastern Clarke County, runs southwest to Osceola, then south to south line of county

Transit

• Osceola station
• List of intercity bus stops in Iowa

Cities

Unincorporated communities

Townships

2020 census

The 2020 census recorded a population of 9,748 in the county, with a population density of 22.5422/sq mi (8.7036/km²). 93.18% of the population reported being of one race. There were 4,268 housing units of which 3,871 were occupied.^[1]

2010 census

The 2010 census recorded a population of 9,286 in the county, with a population density of 21.545/sq mi (8.319/km²). There were 4,086 housing units, of which 3,701 were occupied.^[16]

2000 census

As of the census^[17] of 2000, there were 9,133 people, 3,584 households, and 2,498 families residing in the county. The population density was 21 people per square mile (8.1 people/km²). There were 3,934 housing units at an average density of 9 units per square mile (3.5 units/km²). The racial makeup of the county was 96.64% White, 0.11% Black or African American, 0.33% Native American, 0.35% Asian, 0.03% Pacific Islander, 1.96% from other races, and 0.58% from two or more races. 4.04% of the population were Hispanic or Latino of any race.

There were 3,584 households, out of which 32.10% had children under the age of 18 living with them, 57.80% were married couples living together, 8.30% had a female householder with no husband present, and 30.30% were non-families. 25.90% of all households were made up of individuals, and 13.30% had someone living alone who was 65 years of age or older. The average household size was 2.50 and the average family size was 3.01.

In the county, the population was spread out, with 26.30% under the age of 18, 7.60% from 18 to 24, 26.50% from 25 to 44, 22.50% from 45 to 64, and 17.10% who were 65 years of age or older. The median age was 39 years. For every 100 females there were 97.00 males. For every 100 females age 18 and over, there were 94.00 males.

The median income for a household in the county was $34,474, and the median income for a family was $42,171. Males had a median income of $29,648 versus $20,522 for females. The per capita income for the county was $16,409. About 6.20% of families and 8.50% of the population were below the poverty line, including 12.10% of those under age 18 and 7.70% of those age 65 or over.

Population ranking

The population ranking of the following table is based on the 2020 census of Clarke County.^[1]

† county seat