Los Osos is a Census Designated Place in the coastal zone of San Luis Obispo County. In 2026 Los Osos had 15,200. residents. The community's physical setting is extrordinary. It is the gateway to Montana de Oro State Park, sits on the shores of Morro Bay, and hosts several nature preserves: the El Moro Elfin Forest, the Morro Bay State Marine Reserve, the Los Osos Oaks State Natural Reserve, the Coastal Access Monarch Butterfly Perserve, the Morro Dunes Ecological Reserve, and the Audobon Society's Sweet Springs Nature Preserve.