Lake Forest is a city located in Lake County, Illinois. With a 2020 population of 19,940, it is the 123rd largest city in Illinois and the 1859th largest city in the United States. Lake Forest is currently growing at a rate of 1.00% annually and its population has increased by 2.92% since the most recent census, which recorded a population of 19,375 in 2010. Lake Forest reached it's highest population of 20,059 in 2000. Spanning over 17 miles, Lake Forest has a population density of 1,159 people per square mile.
The average household income in Lake Forest is $265,477 with a poverty rate of 2.58%. The median rental costs in recent years comes to $1,750 per month, and the median house value is $851,900. The median age in Lake Forest is 47.6 years, 45.6 years for males, and 49.9 years for females. For every 100 females there are 96.8 males.