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.