Pierre, SD has a population of 13,959 and is the 2,993rd largest city in the United States. The population density is 1,069 per sq mi which is 9788% higher than the South Dakota average and 1080% higher than the national average. The median age in Pierre is 38 which is approximately 2% higher than the South Dakota average of 37. In Pierre, 58% of the population over 15 years of age are married, 95% speak English and 2% speak Spanish. 70% of Pierre residents were born in South Dakota, 29% were born out of state, 0% were born outside of the United States and 1% were foreign born.