Augusta County is part of the Staunton–Waynesboro Micropolitan Statistical Area.
As of the census of 2000, there were 65,615 people, 24,818 households, and 18,911 families residing in the county. The population density was 68 people per square mile (26/km²). There were 26,738 housing units at an average density of 28 per square mile (11/km²). The racial makeup of the county was 95.02% White, 3.60% Black or African American, 0.15% Native American, 0.28% Asian, 0.02% Pacific Islander, 0.32% from other races, and 0.61% from two or more races. 0.94% of the population were Hispanic or Latino of any race.
There were 24,818 households out of which 33.00% had children under the age of 18 living with them, 63.70% were married couples living together, 8.60% had a female householder with no husband present, and 23.80% were non-families. 20.10% of all households were made up of individuals and 8.10% had someone living alone who was 65 years of age or older. The average household size was 2.56 and the average family size was 2.94.
In the county, the population was spread out with 23.70% under the age of 18, 6.90% from 18 to 24, 29.80% from 25 to 44, 26.80% from 45 to 64, and 12.80% who were 65 years of age or older. The median age was 39 years. For every 100 females there were 101.10 males. For every 100 females age 18 and over, there were 99.80 males.
The median income for a household in the county was $43,045, and the median income for a family was $48,579. Males had a median income of $31,577 versus $24,233 for females. The per capita income for the county was $19,744. About 4.20% of families and 5.80% of the population were below the poverty line, including 6.40% of those under age 18 and 6.60% of those age 65 or over.