Ashton is a city in eastern Spink County, South Dakota, United States. The population was 122 at the 2010 census.
Ashton was founded in 1879, but it was moved and replatted on the current site in 1881 in order to be located on a new railroad line. The town most likely takes its name after Ashton, England. A post office called Ashton has been in operation since 1879.
Ashton is located at 44°59′40″N 98°29′55″W (44.994523, -98.498577).
According to the United States Census Bureau, the city has a total area of 0.44 square miles (1.14 km2), all of it land.
Ashton has been assigned the ZIP code 57424, and the FIPS place code 02540.
As of the census of 2010, there were 122 people, 52 households, and 37 families residing in the city. The population density was 277.3 inhabitants per square mile (107.1/km2). There were 64 housing units at an average density of 145.5 per square mile (56.2/km2). The racial makeup of the city was 100.0% White. Hispanic or Latino of any race were 4.9% of the population.