Artesian is a town in Sanborn County, South Dakota, United States. The population was 129 at the 2020 census. When the first settlement at Artesian was made in 1883, it was called "Diana". A post office called Diana was established in 1883, the name was changed to Denton, and then to Artesian City in 1887, and again to Artesian in 1889. The pres…Artesian is a town in Sanborn County, South Dakota, United States. The population was 129 at the 2020 census. When the first settlement at Artesian was made in 1883, it was called "Diana". A post office called Diana was established in 1883, the name was changed to Denton, and then to Artesian City in 1887, and again to Artesian in 1889. The present name is for the artesian aquifer and artesian wells near the original town site.