Flower fields in Los Osos Valley
The Los Osos Valley is a valley within San Luis Obispo County, in the Central Coast of California region. 
Los Osos Valley lies between southern San Luis Obispo and Baywood-Los Osos. The town of Los Osos is in the valley.
The Irish Hills are along the south side, and five of the Nine Sisters volcanic mountains are along the north.
Los Osos Creek flows through the valley to its mouth on southern Morro Bay.
A prehistoric human habitation site was found at Los Osos Back Bay in the Los Osos Valley, of ancient Chumash tribe.
The Portolá expedition passed through the valley in 1769, as recorded by padre Juan Crespí.
The Los Osos Oaks State Natural Reserve preserves centuries-old Coast live oaks (Quercus agrifolia) growing atop relict sand dunes in the valley, just outside Los Osos. 
The Elfin Forest Natural Area is on the south side of Los Osos Creek's mouth on Morro Bay.
Coordinates: 35°15′00″N 120°41′00″W / 35.2500°N 120.6833°W