Marion, AR has a population of 12,323 and is the 3,345th largest city in the United States. The population density is 608 per sq mi which is 997% higher than the Arkansas average and 572% higher than the national average. The median age in Marion is 34 which is approximately 9% lower than the Arkansas average of 38. In Marion, 58% of the population over 15 years of age are married, 97% speak English and 2% speak Spanish. 47% of Marion residents were born in Arkansas, 51% were born out of state, 0% were born outside of the United States and 2% were foreign born.