Barrios de Washington O
- Oakbrook (2)
- Ogden (5)
- Old Evergreen Highway (2)
- Olde Town (1)
- Olympic West (3)
- Opportunity (3)
- Orchards (2)
- Orchards Area (16)
- Otis Orchards-East Farms (1)
- Outer Bremerton (11)
- Outer Mercer Island (4)
- Outer Silverdale (15)
- Outlying Issaquah (7)
- Outlying Lynnwood-Snohomish (33)
- Outlying McChord (13)
- Outlying Newcastle (10)
- Outlying Puyallup (19)
- Outlying Vancouver (17)
- Overlake (20)