Benton County is part of the Cedar Rapids, IA Metropolitan Statistical Area.

93.04% were non-Hispanic White, 0.45% were Black, 1.81% were Hispanic, 0.13% were Native American, 0.32% were Asian, 0.01% were Native Hawaiian or Pacific Islander and 4.24% were some other race or more than one race.

[12] As of the census[13] of 2000, there were 25,308 people, 9,746 households, and 7,056 families residing in the county.

There were 10,377 housing units at an average density of 14 per square mile (5.4/km2).

The racial makeup of the county was 98.84% White, 0.20% Black or African American, 0.15% Native American, 0.17% Asian, 0.02% Pacific Islander, 0.11% from other races, and 0.52% from two or more races.

23.4% of all households were made up of individuals, and 11.70% had someone living alone who was 65 years of age or older.