Clarion, IA has a population of 2,783 and is the 9,186th largest city in the United States. The population density is 854 per sq mi which is 1464% higher than the Iowa average and 843% higher than the national average. The median age in Clarion is 38 which is approximately 1% lower than the Iowa average of 38. In Clarion, 57% of the population over 15 years of age are married, 85% speak English and 14% speak Spanish. 75% of Clarion residents were born in Iowa, 17% were born out of state, 0% were born outside of the United States and 8% were foreign born.