Interstate 40 (I-40) is an east–west Interstate Highway that has a 284.69-mile (458.16 km) section in the U.S. state of Arkansas, connecting Oklahoma to Tennessee. The route enters Arkansas from the west just north of the Arkansas River near Dora. It travels eastward across the northern portion of the state, connecting the cities of Fort Smith, Clarksville, Russellville, Morrilton, Conway, North Little Rock, Forrest City, and West Memphis. I-40 continues into Tennessee, heading through Memphis. The highway has major junctions with I-540 at Van Buren, I-49 at Alma, I-30 in North Little Rock, and I-55 to Blytheville.

Fort Smith is the third-most populous city in Arkansas, United States, and one of the two county seats of Sebastian County. As of the 2020 census, the population was 89,142. It is the principal city of the Fort Smith, Arkansas–Oklahoma Metropolitan Statistical Area, a region of 298,592 residents that encompasses the Arkansas counties of Crawford, Franklin, and Sebastian, and the Oklahoma counties of LeFlore and Sequoyah.