Preston, ID has a population of 5,252 and is the 6,244th largest city in the United States. The population density is 773 per sq mi which is 3951% higher than the Idaho average and 753% higher than the national average. The median age in Preston is 33 which is approximately 9% lower than the Idaho average of 36. In Preston, 67% of the population over 15 years of age are married, 97% speak English and 3% speak Spanish. 44% of Preston residents were born in Idaho, 52% were born out of state, 0% were born outside of the United States and 4% were foreign born.