Mission, SD has a population of 1,269 and is the 13,687th largest city in the United States. The population density is 2,162 per sq mi which is 17917% higher than the South Dakota average and 2286% higher than the national average. The median age in Mission is 23 which is approximately 38% lower than the South Dakota average of 37. In Mission, 38% of the population over 15 years of age are married, 94% speak English and 0% speak Spanish. 77% of Mission residents were born in South Dakota, 22% were born out of state, 0% were born outside of the United States and 1% were foreign born.