Buffalo is a town in and the county seat of Harding County, South Dakota, United States. The population was 330 at the 2010 census.
Buffalo has been assigned the ZIP code 57720 and the FIPS place code 08140.
Buffalo was established in 1909. It was named for the large herds of buffalo that once roamed the area.
Buffalo, South Dakota, is located at 45°35′5″N 103°32′42″W (45.584845, -103.545001). According to the United States Census Bureau, the town has a total area of 0.55 square miles (1.42 km2), all land.
Buffalo is categorized as being within the 4a USDA hardiness zone, meaning temperatures can drop to as low as -30 to -25 °F.
As of the census of 2010, there were 330 people, 168 households, and 86 families residing in the town. The population density was 600.0 inhabitants per square mile (231.7/km2). There were 220 housing units at an average density of 400.0 per square mile (154.4/km2). The racial makeup of the town was 97.3% White, 0.9% Native American, 0.3% from other races, and 1.5% from two or more races. Hispanic or Latino of any race were 1.5% of the population.
There were 168 households, of which 22.0% had children under the age of 18 living with them, 41.7% were married couples living together, 7.1% had a female householder with no husband present, 2.4% had a male householder with no wife present, and 48.8% were non-families.