Fort Smith, AR has a population of 87,712 and is the 375th largest city in the United States. The population density is 1,389 per sq mi which is 2404% higher than the Arkansas average and 1433% higher than the national average. The median age in Fort Smith is 36 which is approximately 6% lower than the Arkansas average of 38. In Fort Smith, 53% of the population over 15 years of age are married, 79% speak English and 14% speak Spanish. 54% of Fort Smith residents were born in Arkansas, 33% were born out of state, 1% were born outside of the United States and 13% were foreign born.