2020 census
As of the 2020 census, the county had a population of 15,941. The median age was 41.5 years. 24.3% of residents were under the age of 18 and 19.9% of residents were 65 years of age or older. For every 100 females there were 96.3 males, and for every 100 females age 18 and over there were 92.8 males age 18 and over.[13][14]
The racial makeup of the county was 93.9% White, 0.5% Black or African American, 0.3% American Indian and Alaska Native, 0.3% Asian, 0.0% Native Hawaiian and Pacific Islander, 2.1% from some other race, and 2.8% from two or more races. Hispanic or Latino residents of any race comprised 3.4% of the population.[14]
0.0% of residents lived in urban areas, while 100.0% lived in rural areas.[15]
There were 6,270 households in the county, of which 29.6% had children under the age of 18 living with them and 26.4% had a female householder with no spouse or partner present. About 30.0% of all households were made up of individuals and 15.2% had someone living alone who was 65 years of age or older.[13]
There were 7,366 housing units, of which 14.9% were vacant. Among occupied housing units, 76.2% were owner-occupied and 23.8% were renter-occupied. The homeowner vacancy rate was 1.7% and the rental vacancy rate was 6.5%.[13]
Casey County is the county in the United States with the highest proportion of Midwest Beachy Amish adherents, with 1.11% of the population in 2020 subscribing to the denomination.[16]
2000 census
As of the census of 2000, there were 15,447 people, 6,260 households, and 4,419 families residing in the county. The population density was 35 per square mile (14/km2). There were 7,242 housing units at an average density of 16 per square mile (6.2/km2). The racial makeup of the county was 98.30% White, 0.33% Black or African American, 0.28% Native American, 0.06% Asian, 0.05% Pacific Islander, 0.31% from other races, and 0.66% from two or more races. 1.28% of the population were Hispanic or Latino of any race.
There were 6,260 households, out of which 31.00% had children under the age of 18 living with them, 56.10% were married couples living together, 10.80% had a female householder with no husband present, and 29.40% were non-families. 26.80% of all households were made up of individuals, and 12.60% had someone living alone who was 65 years of age or older. The average household size was 2.44 and the average family size was 2.94.
24.50% of the population was under the age of 18, 8.20% from 18 to 24, 27.50% from 25 to 44, 24.70% from 45 to 64, and 15.10% who were 65 years of age or older. The median age was 38 years. For every 100 females there were 95.60 males. For every 100 females age 18 and over, there were 92.60 males.
The median income for a household in the county was $21,580, and the median income for a family was $27,044. Males had a median income of $22,283 versus $17,885 for females. The per capita income for the county was $12,867. About 20.70% of families and 25.50% of the population were below the poverty line, including 32.10% of those under age 18 and 29.60% of those age 65 or over.
