Le Mars, IA has a population of 9,826 and is the 3,990th largest city in the United States. The population density is 1,093 per sq mi which is 1901% higher than the Iowa average and 1106% higher than the national average. The median age in Le Mars is 39 which is approximately 4% higher than the Iowa average of 38. In Le Mars, 62% of the population over 15 years of age are married, 94% speak English and 5% speak Spanish. 76% of Le Mars residents were born in Iowa, 21% were born out of state, 0% were born outside of the United States and 3% were foreign born.