Harvey, IL has a population of 25,625 and is the 1,682nd largest city in the United States. The population density is 4,129 per sq mi which is 1757% higher than the Illinois average and 4457% higher than the national average. The median age in Harvey is 35 which is approximately 5% lower than the Illinois average of 37. In Harvey, 34% of the population over 15 years of age are married, 78% speak English and 19% speak Spanish. 73% of Harvey residents were born in Illinois, 16% were born out of state, 1% were born outside of the United States and 10% were foreign born.