Barrington, IL has a population of 10,449 and is the 3,819th largest city in the United States. The population density is 2,268 per sq mi which is 920% higher than the Illinois average and 2404% higher than the national average. The median age in Barrington is 44 which is approximately 17% higher than the Illinois average of 37. In Barrington, 67% of the population over 15 years of age are married, 89% speak English and 4% speak Spanish. 64% of Barrington residents were born in Illinois, 28% were born out of state, 0% were born outside of the United States and 7% were foreign born.