Douglas County is one of the 36 counties in the U.S. state of Oregon. As of the 2020 census, the population was 111,201. The county seat is Roseburg. The county is named after Stephen A. Douglas, an American politician who supported Oregon statehood. Douglas County comprises the Roseburg, OR Micropolitan Statistical Area. In regards to area, Douglas County is the largest county west of the Oregon Cascades.

Roseburg is a city in the U.S. state of Oregon. It is in the Umpqua River Valley in southern Oregon and is the county seat and most populous city of Douglas County. Founded in 1851, the population was 23,683 at the 2020 census, making it the principal city of the Roseburg, Oregon Micropolitan Statistical Area. The community developed along both sides of the South Umpqua River and is traversed by Interstate 5. Traditionally a lumber industry town, Roseburg was the original home of Roseburg Forest Products, which is now based in nearby Springfield.