The River Bend is a small region in western central Illinois and Southern Illinois that comprises parts of three counties: Madison, Calhoun, and Jersey. The name comes from a section of Mississippi River that flows roughly west to east instead of the usual north to south, causing a bend in the river. It is also part of the Greater St. Louis Metropolitan area in the Metro East region. In this area, two other major rivers, the Missouri and the Illinois join the Mississippi River. This section of the Mississippi River is known as the Alton Lake.
The part in Madison County that locals consider part of the River Bend is the section north of Interstate 270 and west of Illinois Route 159.