[2] It is named for Francis Marion, a brigadier general from South Carolina in the American Revolutionary War.

[11] As of the census[12] of 2000, there were 32,052 people, 12,017 households, and 8,532 families residing in the county.

The racial makeup of the county was 97.46% White, 0.42% Black or African American, 0.19% Native American, 1.03% Asian, 0.04% Pacific Islander, 0.22% from other races, and 0.64% from two or more races.

25.60% of all households were made up of individuals, and 11.90% had someone living alone who was 65 years of age or older.

The population ranking of the following table is based on the 2020 census of Marion County.