McCook is a village in Cook County, Illinois, United States, and is an industrial suburb of Chicago.

The Outlaws Motorcycle Club was established in McCook in 1935 when Old Route 66 passed through the town.

In 1995, the former Universal Oil Products Riverside Laboratory in McCook was awarded with National Historic Chemical Landmark status.

McCook is home to a large amount of heavy industry, including portions of Vulcan Materials Company McCook Quarry, UOP, and the Electro-Motive Diesel (EMD) railroad locomotive plant.

Known as the LaGrange plant for its mailing address (McCook does not have its own post office), EMD produced most of their locomotives there from 1935 to 1991, when parent company General Motors moved all final-assembly operations to London, Ontario.

The LaGrange plant continues to manufacture locomotive parts and engines, and also serves as the EMD U.S. headquarters.

Pace provides bus service on Route 330 connecting McCook to destinations across the region.