Cullman is the largest city and county seat of Cullman County, Alabama, United States. It is located along Interstate 65, about 50 miles (80 km) north of Birmingham and about 55 miles (89 km) south of Huntsville. As of the 2020 census it had a population of 18,213, with an estimated population of 19,251 in 2022.

U.S. Route 31 or U.S. Highway 31 (US 31) is a major north–south U.S. highway connecting southern Alabama to northern Michigan. Its southern terminus is at an intersection with US 90/US 98 in Spanish Fort, Alabama. Its northern terminus is at an interchange with Interstate 75 (I-75) south of Mackinaw City, Michigan.