Mount Vernon is a city in Davison County, South Dakota, United States. The population was 462 at the 2010 census. It is part of the Mitchell, South Dakota Micropolitan Statistical Area.
The town takes its name from Mount Vernon, the estate of George Washington; an early variant name was Arlandtown.
Mount Vernon is located at 43°42′44″N 98°15′41″W (43.712155, -98.261264).
According to the United States Census Bureau, the city has a total area of 0.35 square miles (0.91 km2), all land.
Mount Vernon has been assigned the ZIP code 57363 and the FIPS place code 44100.
As of the census of 2010, there were 462 people, 178 households, and 125 families residing in the city. The population density was 1,320.0 inhabitants per square mile (509.7/km2). There were 205 housing units at an average density of 585.7 per square mile (226.1/km2). The racial makeup of the city was 92.6% White, 5.4% Native American, 0.4% Pacific Islander, and 1.5% from two or more races. Hispanic or Latino of any race were 2.2% of the population.
There were 178 households, of which 39.9% had children under the age of 18 living with them, 59.0% were married couples living together, 6.2% had a female householder with no husband present, 5.1% had a male householder with no wife present, and 29.8% were non-families.