Missouri is a state in the Midwest region of the United States that is named for the Missouri River. It is bordered by Iowa, Illinois, Kentucky, Tennessee, Arkansas, Oklahoma, Kansas and Nebraska. Missouri is the 18th most populous state with an estimated population of 5,911,605 in 2008. Missouri's capital is Jefferson City and the four largest cities are Columbia, Kansas City, St. Louis, and Springfield.

Missouri has both Midwestern and Southern cultural influences and is a transition between the eastern and western United States, as St. Louis is often called the "western-most eastern city" and Kansas City the "eastern-most western city." Missouri's geography is highly varied, with the northern part of the state lying in dissected till plains, the southern part in the Ozark Mountains (dissected plateau), and the Missouri River divides the two. The confluence of the Mississippi and Missouri rivers is located near St. Louis. Missouri generally has cold winters and hot and humid summers.