River Grove, IL has a population of 10,248 and is the 3,875th largest city in the United States. The population density is 4,287 per sq mi which is 1828% higher than the Illinois average and 4631% higher than the national average. The median age in River Grove is 39 which is approximately 5% higher than the Illinois average of 37. In River Grove, 61% of the population over 15 years of age are married, 50% speak English and 18% speak Spanish. 64% of River Grove residents were born in Illinois, 3% were born out of state, 2% were born outside of the United States and 30% were foreign born.