Lake Forest is a city located in Illinois. With a 2020 population of 19,376, it is the 129th largest city in Illinois and the 1901st largest city in the United States. Lake Forest is currently declining at a rate of -0.36% annually but its population has increased by 0.01% 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 1,126 people per square mile.
The average household income in Lake Forest is $269,555 with a poverty rate of 2.80%. The median rental costs in recent years comes to $1,831 per month, and the median house value is $842,900. The median age in Lake Forest is 47.8 years, 46.2 years for males, and 49.9 years for females. For every 100 females there are 94.0 males.