Roslyn, SD has a population of 197 and is the 24,507th largest city in the United States. The population density is 1,002 per sq mi which is 9167% higher than the South Dakota average and 1006% higher than the national average. The median age in Roslyn is 54 which is approximately 48% higher than the South Dakota average of 37. In Roslyn, 76% of the population over 15 years of age are married, 99% speak English and 0% speak Spanish. 81% of Roslyn residents were born in South Dakota, 18% were born out of state, 1% were born outside of the United States and 1% were foreign born.