Lake Barrington, IL has a population of 4,927 and is the 6,547th largest city in the United States. The population density is 863 per sq mi which is 288% higher than the Illinois average and 852% higher than the national average. The median age in Lake Barrington is 58 which is approximately 54% higher than the Illinois average of 37. In Lake Barrington, 73% of the population over 15 years of age are married, 90% speak English and 4% speak Spanish. 60% of Lake Barrington residents were born in Illinois, 31% were born out of state, 1% were born outside of the United States and 8% were foreign born.