Oak Brook is a village in DuPage County with a small portion in Cook County in Illinois. The population was 7,883 at the 2010 census. This suburb of Chicago has the headquarters of several companies and organizations including Ace Hardware, Blistex, Federal Signal, CenterPoint Properties, Sanford L.P., TreeHouse Foods, and Lions Clubs International. It is the former corporate home of McDonald's and Ferrara Candy.