Lake Mills, IA has a population of 2,027 and is the 10,943rd largest city in the United States. The population density is 752 per sq mi which is 1276% higher than the Iowa average and 730% higher than the national average. The median age in Lake Mills is 43 which is approximately 13% higher than the Iowa average of 38. In Lake Mills, 71% of the population over 15 years of age are married, 98% speak English and 0% speak Spanish. 55% of Lake Mills residents were born in Iowa, 44% were born out of state, 0% were born outside of the United States and 1% were foreign born.