Coos Bay is a city located in Coos County, Oregon, United States, where the Coos River enters Coos Bay on the Pacific Ocean. The city borders the city of North Bend, and together they are often referred to as one entity called either Coos Bay-North Bend or Oregon's Bay Area. Coos Bay's population as of the 2020 census was 15,985 residents, making it the most populous city on the Oregon Coast. Oregon's Bay Area is estimated to be home to 32,308.