Grandwood Park is a census-designated place (CDP) in Warren Township, Lake County, Illinois, United States.

[4] Before the Industrial Revolution had made its way to the western Great Lakes, the land remained in the hands of the Potawatomi until the 1833 Treaty of Chicago.

[5] Small farm families dotted the land for several decades until 1873, of which a train station was built along the Chicago, Milwaukee, St. Paul and Pacific Railroad in the neighboring village (once an unincorporated area) of Gurnee.

[7][8] This farmer is credited for constructing a dam that barred Mill Creek and consequently formed Grandwood Lake that same year.

[7] Flooding averaging a foot in depth consumed adjoining Lake Park and nearby residences.

For two weeks following the incident a variety of fish were found swimming on the park grounds and in yards, notably grass carp.

During a Board of Commissioners session on February 8, 2023, it was proposed that an electric light should be added to Lake Park in order to illuminate the dam.

[13] In 2020 the original bridge built across Mill Creek along North Hutchins Road in 1969, along with the culvert, were dismantled and rebuilt.

[15] Pace Bus - Route 565 runs along Grand Avenue between Waukegan's Metra Station and the College of Lake County in Grayslake.

As it is fed by Mill Creek, the shallow waters of Grandwood Lake harbor a variety of different freshwater fish.

This includes an abundancy of many types of panfish such as Bluegill, Pumpkinseed, Redear Sunfish, Warmouth, and Yellow Perch.

The small marsh-like environment surrounding Grandwood Lake is home to variety of song and water birds.