Barrios de Washington O
- Oakbrook (1)
- Ogden (7)
- Old Evergreen Highway (1)
- Old West Side (2)
- Olde Town (5)
- Olympic West (1)
- Opportunity (6)
- Orchards (1)
- Orchards Area (24)
- Outer Bremerton (19)
- Outer Mercer Island (12)
- Outer Silverdale (20)
- Outlying Issaquah (4)
- Outlying Lynnwood-Snohomish (35)
- Outlying McChord (15)
- Outlying Newcastle (9)
- Outlying Puyallup (23)
- Outlying Vancouver (20)
- Overlake (25)