Greenup is a village in Cumberland County, Illinois, United States, along the Embarras River. The population was 1,365 at the 2020 census. It is part of the Charleston–Mattoon Micropolitan Statistical Area. Greenup received its name from National Road surveyor, William C. Greenup who platted the town in 1834. He was one of the supervisors hired to oversee construction of the National Road in Illinois, surveying the original alignment from Marshall to Vandalia during the 1830s.