Preston, IA has a population of 1,037 and is the 14,924th largest city in the United States. The population density is 1,077 per sq mi which is 1871% higher than the Iowa average and 1089% higher than the national average. The median age in Preston is 38 which is approximately equal to the Iowa average of 38. In Preston, 62% of the population over 15 years of age are married, 99% speak English and 1% speak Spanish. 92% of Preston residents were born in Iowa, 7% were born out of state, 0% were born outside of the United States and 1% were foreign born.