Many local park districts have picnic areas that are available for use by local residents and businesses. The following is a list of some local park districts and links to their websites. The list is not exclusive. Many other sites and locations can be found on the internet, but we will be happy to assist you in getting information on your desired location/venue.

For larger events, private picnic or camp grounds and county forest preserves that surround the Chicago area are a great resource. Cook County has instituted a network that consists of five large group sites around Cook County specifically intended for groups of 500 or more. Their website has more information as well as a listing of these locations.

Cook County Forest Preserves - Picnic Permits
Lake County Forest Preserves - Picnic Permits
Will County Forest Preserves - Picnic Permits
Kane County Forest Preserves - Picnic Permits
The Grove - in Glenview

Please check with your local park districts as many have public picnic facilities.
Here are only a few listings for suburbs outside the Chicago area:

Addison Park District
Arlington Heights Park District
Barrington Park District
Bartlett Park District
Bloomingdale Park District
Buffalo Grove Park District
Butterfield Park District
Carol Stream Park District
City of Aurora - Department of Parks
City of McHenry
Crystal Lake Park District
Deerfield Park District
Downers Grove Park District