Post-Revolutionary and 19th-century history

• 1780s - The rare American wildflower, Oconee Bell, was first recorded by French botanist André Michaux.
• 1780s - Colonel Benjamin Cleveland and a group of Revolutionary veterans received land grants from the state of Georgia (which then claimed this area according to their colonial charter), in lieu of payment for service, and settled in present-day Oconee County.
• 1787 - Georgia withdrew its claims to the land between the Tugaloo and Keowee rivers by the Treaty of Beaufort with South Carolina.
• 1816 - Under pressure from encroaching European Americans, the Cherokee sold their remaining South Carolina land.
• 1850s - The largest town in the county was Tunnel Hill, located above Stumphouse Mountain Tunnel.
• 1868 - Oconee County was formed by the state legislature dividing Pickens County. Walhalla was designated as the county seat.
• 1870 - Air Line Railroad built a railroad through the county; it stimulated development at stops known as Seneca and Westminster
• 1893 - Newry was established as a mill village to house workers of the Courtenay Manufacturing Company, a textile mill that produced cotton, wool, and other textile products.^[6]

National protected areas

• Ellicott Rock Wilderness (part)
• Sumter National Forest (part)

State and local protected areas/sites

• Brasstown Creek Heritage Preserve/Wildlife Management Area^[8]
• Buzzard Roost Heritage Preserve/Wildlife Management Area^[8]
• Chau Ram County Park
• Devils Fork State Park
• High Falls County Park
• Horsepasture River
• Lake Hartwell State Recreation Area
• Oconee State Park
• Oconee Station State Historic Site
• Piedmont Forestry Center
• Poe Creek State Forest (part)
• South Cove County Park
• Stumphouse Mountain Heritage Preserve/Wildlife Management Area^[8]
• Sumter National Forest - Andrew Pickens Ranger District^[8]
• W.P. Anderson City Park
• Yellow Branch Falls Recreation Area

Major water bodies

• Chattooga River
• Keowee River
• Lake Hartwell
• Lake Jocassee
• Lake Keowee
• Little River
• Savannah River

Adjacent counties

Major highways

Major infrastructure

• Oconee County Regional Airport

2020 census

As of the 2020 census, there were 78,607 people, 31,530 households, and 21,214 families residing in the county.

2010 census

At the 2010 census,^[13] there were 74,273 people, 30,676 households, and 21,118 families living in the county.^[15] The population density was 118.6 inhabitants per square mile (45.8 inhabitants/km²). There were 38,763 housing units at an average density of 61.9 units per square mile (23.9 units/km²).^[16] The racial makeup of the county was 87.8% white, 7.6% black or African American, 0.6% Asian, 0.2% American Indian, 2.3% from other races, and 1.6% from two or more races. Those of Hispanic or Latino origin made up 4.5% of the population.^[15] In terms of ancestry,^[17]

Of the 30,676 households, 28.2% had children under the age of 18 living with them, 53.8% were married couples living together, 11.2% had a female householder with no husband present, 31.2% were non-families, and 26.2% of all households were made up of individuals. The average household size was 2.40 and the average family size was 2.86. The median age was 43.4 years.^[15]

The median income for a household in the county was $42,266 and the median income for a family was $52,332. Males had a median income of $40,943 versus $29,841 for females. The per capita income for the county was $24,055. About 11.8% of families and 16.6% of the population were below the poverty line, including 22.7% of those under age 18 and 9.4% of those age 65 or over.^[18]

2000 census

At the 2000 census,^[19] there were 66,215 people, 27,283 households, and 19,589 families living in the county. The population density was 106 people per square mile (41 people/km²). There were 32,383 housing units at an average density of 52 units per square mile (20 units/km²). The racial makeup of the county was 89.14% White, 8.38% Black or African American, 0.22% Native American, 0.35% Asian, 0.02% Pacific Islander, 1.06% from other races, and 0.82% from two or more races. 2.36% of the population were Hispanic or Latino of any race. 26.5% were of American, 13.1% Irish, 11.9% German and 10.5% English ancestry according to Census 2000.

There were 27,283 households, out of which 28.50% had children under the age of 18 living with them, 57.80% were married couples living together, 10.10% had a female householder with no husband present, and 28.20% were non-families. 24.70% of all households were made up of individuals, and 9.50% had someone living alone who was 65 years of age or older. The average household size was 2.40 and the average family size was 2.85.

In the county, the population was spread out, with 22.90% under the age of 18, 8.00% from 18 to 24, 27.40% from 25 to 44, 26.20% from 45 to 64, and 15.60% who were 65 years of age or older. The median age was 40 years. For every 100 females, there were 96.70 males. For every 100 females age 18 and over, there were 93.50 males.

The median income for a household in the county was $36,666, and the median income for a family was $43,047. Males had a median income of $31,032 versus $22,156 for females. The per capita income for the county was $18,965. About 7.60% of families and 10.80% of the population were below the poverty line, including 14.00% of those under age 18 and 12.90% of those age 65 or over.

Cities

• Seneca (largest community)
• Walhalla (county seat)
• Westminster

Towns

• Salem
• West Union

Census-designated places

Unincorporated communities