Interstate 155 (I-155) is an east–west auxiliary route of Interstate 55 (I-55) that runs through the Bootheel of Missouri and the northwestern corner of Tennessee. It begins south of Hayti, Missouri at I-55, passes eastward through Caruthersville, and crosses the Mississippi River on the Caruthersville Bridge into Tennessee. The route then proceeds to Dyersburg, Tennessee, where it terminates at U.S. Route 51 (US 51). I-155 is the only road that directly connects Missouri and Tennessee, and is concurrent with US 412 for its entire length.

West Tennessee is one of the three Grand Divisions of Tennessee that roughly comprises the western quarter of the state. The region includes 21 counties between the Tennessee and Mississippi rivers, delineated by state law. Its geography consists primarily of flat lands with rich soil and vast floodplain areas of the Mississippi River. Of the three regions, West Tennessee is the most sharply defined geographically, and is the lowest-lying. It is both the least populous and smallest, in land area, of the three Grand Divisions. Its largest city is Memphis, the state's second most populous city.