Harvey, IL has a population of 25,225 and is the 1,680th largest city in the United States. The population density is 3,999 per sq mi which is 1630% higher than the Illinois average and 4314% higher than the national average. The median age in Harvey is 34 which is approximately 9% lower than the Illinois average of 37. In Harvey, 36% of the population over 15 years of age are married, 82% speak English and 17% speak Spanish. 76% of Harvey residents were born in Illinois, 16% were born out of state, 0% were born outside of the United States and 8% were foreign born.