Barnum is a city in Carlton County, Minnesota, United States.

According to the United States Census Bureau, the city has an area of 1,000 square miles (2,589.99 km2), all land.

The Carlton County Agricultural and Industrial Society owns and operates the fairgrounds.

The fair features livestock shows, agricultural exhibits, carnival rides, live music, and a demolition derby.

30.9% of all households were made up of individuals, and 14.9% had someone living alone who was 65 years of age or older.

The racial makeup of the city was 97.33% White, 1.52% Native American, and 1.14% from two or more races.

20.0% were of Norwegian, 17.2% German, 13.0% American, 11.7% Swedish and 6.7% Finnish ancestry according to Census 2000.

31.0% of all households were made up of individuals, and 16.4% had someone living alone who was 65 years of age or older.