Iowa Falls, IA has a population of 5,176 and is the 6,304th largest city in the United States. The population density is 966 per sq mi which is 1668% higher than the Iowa average and 966% higher than the national average. The median age in Iowa Falls is 42 which is approximately 11% higher than the Iowa average of 38. In Iowa Falls, 58% of the population over 15 years of age are married, 95% speak English and 4% speak Spanish. 74% of Iowa Falls residents were born in Iowa, 22% were born out of state, 1% were born outside of the United States and 3% were foreign born.