Adjacent counties

• Belmont County (north)
• Marshall County, West Virginia (northeast)
• Wetzel County, West Virginia (east)
• Tyler County, West Virginia (southeast)
• Washington County (south)
• Noble County (west)

Major highways

National protected area

• Wayne National Forest (part)

2000 census

As of the census^[14] of 2000, there were 15,180 people, 6,021 households, and 4,413 families living in the county. The population density was 33 people per square mile (13 people/km²). There were 7,212 housing units at an average density of 16 units per square mile (6.2/km²). The racial makeup of the county was 98.72% White, 0.26% Black or African American, 0.15% Native American, 0.07% Asian, 0.01% Pacific Islander, 0.11% from other races, and 0.67% from two or more races. 0.41% of the population were Hispanic or Latino of any race.

There were 6,021 households, out of which 29.50% had children under the age of 18 living with them, 61.70% were married couples living together, 8.10% had a female householder with no husband present, and 26.70% were non-families. 24.00% of all households were made up of individuals, and 11.50% 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 2.96.

In the county, the population was spread out, with 23.60% under the age of 18, 7.10% from 18 to 24, 25.90% from 25 to 44, 27.20% from 45 to 64, and 16.30% who were 65 years of age or older. The median age was 41 years. For every 100 females there were 97.50 males. For every 100 females age 18 and over, there were 96.10 males.

The median income for a household in the county was $30,467, and the median income for a family was $36,297. Males had a median income of $33,308 versus $19,628 for females. The per capita income for the county was $15,096. About 11.00% of families and 13.90% of the population were below the poverty line, including 18.30% of those under age 18 and 11.40% of those age 65 or over.

2010 census

As of the 2010 United States Census, there were 14,642 people, 6,065 households, and 4,183 families living in the county.^[15] The population density was 32.1 inhabitants per square mile (12.4/km²). There were 7,567 housing units at an average density of 16.6 units per square mile (6.4 units/km²).^[16] The racial makeup of the county was 98.1% white, 0.4% black or African American, 0.1% Asian, 0.1% American Indian, 0.1% from other races, and 1.2% from two or more races. Those of Hispanic or Latino origin made up 0.4% of the population.^[15] In terms of ancestry, 34.8% were German, 14.5% were Irish, 10.6% were English, and 9.6% were American.^[17]

Of the 6,065 households, 27.3% had children under the age of 18 living with them, 56.0% were married couples living together, 8.6% had a female householder with no husband present, 31.0% were non-families, and 27.3% of all households were made up of individuals. The average household size was 2.39 and the average family size was 2.87. The median age was 44.7 years.^[15]

The median income for a household in the county was $37,030 and the median income for a family was $43,261. Males had a median income of $39,261 versus $24,922 for females. The per capita income for the county was $18,738. About 12.3% of families and 17.3% of the population were below the poverty line, including 26.7% of those under age 18 and 12.3% of those age 65 or over.^[18]

Villages

Townships

Census-designated places

• Hannibal
• Sardis

Unincorporated communities

• Cameron
• Duffy
• Fly
• Laings
• Malaga
• Rinard Mills
• Sardis
• Sycamore Valley

Ghost town

• Quarry