Sun Valley, ID has a population of 1,398 and is the 13,106th largest city in the United States. The population density is 146 per sq mi which is 666% higher than the Idaho average and 61% higher than the national average. The median age in Sun Valley is 60 which is approximately 68% higher than the Idaho average of 36. In Sun Valley, 62% of the population over 15 years of age are married, 87% speak English and 7% speak Spanish. 8% of Sun Valley residents were born in Idaho, 78% were born out of state, 1% were born outside of the United States and 13% were foreign born.