Hannibal is a city in Marion and Ralls counties in the U.S. state of Missouri. Hannibal is located at the intersection of Interstate 72 and U.S. Routes 24, 36 and 61, approximately 100 miles (160 km) northwest of St. Louis. According to the 2010 U.S. Census the population was 17,606. The Hannibal Micropolitan Statistical Area is composed of Marion and Ralls Counties.
Interstate 72 was extended into Hannibal across the Mark Twain Memorial Bridge in 2000. Interstate 72 extends west to the intersection with U.S. Route 61. Future plans call for extending Interstate 72 west along U.S. Route 36 to Cameron, MO giving Hannibal an east-west link connecting Kansas City to Springfield, IL. U.S. Route 61 connects to Saint Louis to the south and is part of the Avenue of the Saints corridor that links to Saint Paul, MN.
Hannibal Regional Airport, (formerly Hannibal Municipal Airport) was named William P. Lear Field in 2003 in honor of the inventor of the Lear Jet. The airport is located 4 miles (6.4 km) west of the southern area and has one runway 4,400' x 100'.