Roseburg is a city in the U.S. state of Oregon. Located in the Umpqua River Valley in Southern Oregon, it is the county seat and most populous city of Douglas County. Founded in 1851, the population was 21,181 at the 2010 census, making it the principal city of the Roseburg, OR Micropolitan Statistical Area. Interstate 5 runs through the community along with the South Umpqua River. Traditionally a timber town, Roseburg is the home of Roseburg Forest Products.