Coos Bay is a bay on the coast of Oregon in the United States.
Coos Bay may also refer to:
- Coos Bay, Oregon, a city in Oregon
- USS Coos Bay (AVP-25), a United States Navy seaplane tender in commission from 1943 to 1946
- USCGC Coos Bay (WAVP-376), later WHEC-376, a United States Coast Guard cutter in commission from 1949 to 1966