Coos County is one of the 36 counties in the U.S. state of Oregon. As of the 2020 census, the population was 64,929. The county seat is Coquille. The county was formed from the western parts of Umpqua and Jackson counties. It is named after a tribe of Native Americans who live in the region. Coos County comprises the Coos Bay, OR Micropolitan Statistical Area.