Oak Forest is a city in Cook County, Illinois, United States. The city is out 24 miles south-southwest of downtown Chicago in Bremen Township…Oak Forest is a city in Cook County, Illinois, United States. The city is out 24 miles south-southwest of downtown Chicago in Bremen Township. Per the 2020 census, the population was 27,478. Human habitation in Oak Forest began during the early Holocene. This is made evident by the remains of hunting camps on what would become the grounds of the city's hospital. Several millennia later, the final known indigenous settlement in Oak Forest, a Potawatomi longhouse village, was established nearby. However, it was abandoned by the 1620s.
