Oak Brook is a city located in Illinois. With a 2020 population of 7,918, it is the 257th largest city in Illinois and the 3658th largest city in the United States . Oak Brook is currently declining at a rate of -0.62% annually but its population has increased by 0.44% since the most recent census, which recorded a population of 7,883 in 2010. Oak Brook reached it's highest population of 9,178 in 1990. Spanning over 8 miles, Oak Brook has a population density of 994 people per square mile.
The average household income in Oak Brook is $236,686 with a poverty rate of 4.86%. The median rental costs in recent years comes to - per month, and the median house value is $801,100. The median age in Oak Brook is 56.1 years, 54.8 years for males, and 56.7 years for females.