Gladbrook, IA has a population of 886 and is the 15,901st largest city in the United States. The population density is 1,273 per sq mi which is 2229% higher than the Iowa average and 1305% higher than the national average. The median age in Gladbrook is 47 which is approximately 23% higher than the Iowa average of 38. In Gladbrook, 69% of the population over 15 years of age are married, 97% speak English and 1% speak Spanish. 84% of Gladbrook residents were born in Iowa, 16% were born out of state, 0% were born outside of the United States and 0% were foreign born.