Missouri Route 5 is the longest state highway in Missouri and the only Missouri state highway to traverse the entire state. To the north, it continues into Iowa as Iowa Highway 5 and to the south it enters Arkansas as Arkansas Highway 5 as part of a three state 650 mile highway 5. With only a few exceptions, it is mostly a two-lane for its entire length.

Iowa Highway 5 is a highway in southern Iowa. It is a north–south highway with a length of 105 miles (169 km). It is the northernmost segment of a three-state "Highway 5" also involving Missouri Route 5 and Arkansas Highway 5. Portions of the highway are freeway and expressway. It had previously been designated Iowa Highway 60. The southern terminus of Iowa Highway 5 is at the Missouri border southwest of Cincinnati. Its northern terminus is at Interstate 35 at West Des Moines.