Homberg is an unincorporated community in Pope County, Illinois, United States, near the Ohio River and about five miles (8 km) southwest of the county seat of Golconda. It is on a flat riverbed, a former channel of the Ohio River when the river turned west and flowed a bit south of the present Illinois Route 146, crossing the current Mississippi River south of Cape Girardeau, Missouri, eventually merging with the Mississippi of that time, near Memphis, Tennessee.