Adjacent counties

• Noble County (north)
• Monroe County (northeast)
• Tyler County, West Virginia (east)
• Pleasants County, West Virginia (southeast)
• Wood County, West Virginia (south)
• Athens County (southwest)
• Morgan County (northwest)

Major highways

Protected areas

• Wayne National Forest (part)
• Boord State Nature Preserve

2000 census

As of the census^[11] of 2000, there were 63,251 people, 25,137 households, and 17,671 families living in the county. The population density was 100 inhabitants per square mile (39 inhabitants/km²). There were 27,760 housing units at an average density of 44 units per square mile (17/km²). The racial makeup of the county was 97.33% White, 0.92% Black or African American, 0.24% Native American, 0.43% Asian, 0.05% Pacific Islander, 0.13% from other races, and 0.89% from two or more races. 0.51% of the population were Hispanic or Latino of any race. 29.5% were of German, 23.4% American, 12.3% English and 11.0% Irish ancestry according to Census 2000.

There were 25,137 households, out of which 30.90% had children under the age of 18 living with them, 57.90% were married couples living together, 9.10% had a female householder with no husband present, and 29.70% were non-families. 25.40% of all households were made up of individuals, and 11.20% had someone living alone who was 65 years of age or older. The average household size was 2.45 and the average family size was 2.93.

In the county, the population was spread out, with 23.50% under the age of 18, 8.80% from 18 to 24, 27.50% from 25 to 44, 25.10% from 45 to 64, and 15.00% who were 65 years of age or older. The median age was 39 years. For every 100 females there were 94.60 males. For every 100 females age 18 and over, there were 91.00 males.

The median income for a household in the county was $34,275, and the median income for a family was $41,605. Males had a median income of $32,034 versus $21,346 for females. The per capita income for the county was $18,082. About 8.60% of families and 11.40% of the population were below the poverty line, including 15.70% of those under age 18 and 10.20% of those age 65 or over.

2010 census

As of the 2010 United States Census, there were 61,778 people, 25,587 households, and 17,092 families living in the county.^[12] The population density was 97.8 inhabitants per square mile (37.8 inhabitants/km²). There were 28,367 housing units at an average density of 44.9 units per square mile (17.3 units/km²).^[13] The racial makeup of the county was 96.5% white, 1.1% black or African American, 0.6% Asian, 0.2% American Indian, 0.2% from other races, and 1.5% from two or more races. Those of Hispanic or Latino origin made up 0.7% of the population.^[12] In terms of ancestry, 29.3% were German, 16.7% were Irish, 11.8% were English, and 10.7% were American.^[14]

Of the 25,587 households, 28.4% had children under the age of 18 living with them, 52.5% were married couples living together, 10.0% had a female householder with no husband present, 33.2% were non-families, and 28.1% of all households were made up of individuals. The average household size was 2.34 and the average family size was 2.84. The median age was 43.0 years.^[12]

The median income for a household in the county was $41,654 and the median income for a family was $53,131. Males had a median income of $42,460 versus $28,828 for females. The per capita income for the county was $22,786. About 10.8% of families and 15.2% of the population were below the poverty line, including 22.5% of those under age 18 and 10.0% of those age 65 or over.^[15]

Cities

• Belpre
• Marietta (county seat)

Villages

• Beverly
• Lower Salem
• Lowell
• Macksburg
• Matamoras

Townships

Census-designated places

• Devola
• Little Hocking
• Newport
• Reno
• Vincent
• Waterford

Unincorporated communities