Des Plaines, river, 110 mi (177 km) long, rising in SE Wis., and flowing S and SW through NE Ill., joining the Kankakee River S of Joliet, Ill., to form the Illinois River. The lower Des Plaines is part of the Illinois Waterway.
Des Plaines (dĕs plānz), city (1990 pop. 53,223), Cook co., NE Ill., a suburb of Chicago on the Des Plaines River; inc. 1925. Among its manufactures are chemicals and electronic equipment. It was founded in the 1830s as the town of Rand; the name was changed in 1869, and Riverview was annexed in 1925. O'Hare International Airport is to the south.