As of the census[14] of 2000, there were 28,056 people, 10,825 households, and 7,501 families residing in the county.

The racial makeup of the county was 98.81% White, 0.06% Black or African American, 0.15% Native American, 0.21% Asian, 0.01% Pacific Islander, 0.27% from other races, and 0.48% from two or more races.

90.9% spoke English, 3.5% German, 1.8% Norwegian, 1.2% Pennsylvania Dutch and 1.0% Spanish as their first language.

26.70% of all households were made up of individuals, and 13.70% had someone living alone who was 65 years of age or older.

[16] Religion in Vernon County,according to ARDA (2020) [17] The county is home to the headquarters of Organic Valley, the world's largest cooperative of family farmers.

Vernon County had been a Democratic-leaning county since the 1988 presidential election, but Republican Donald Trump won a plurality of the vote in 2016 and a majority of the vote in 2020 and 2024.