Jesup is a city in Buchanan County and partly in Black Hawk County in the U.S. state of Iowa. The population was 2,508 at the time of the 2020 census. It was named for Morris Ketchum Jesup, president of the Dubuque and Sioux City Railroad. The Black Hawk County portion of Jesup is part of the Waterloo–Cedar Falls Metropolitan Statistical Area. The community of Jesup has undergone many changes in recent years.