- Camano
- Carbonado
- Carlsborg
- Carnation
- Cascade Valley
- Cashmere
- Cathan
- Cathcart
- Cathlamet
- Centerville
- Central Park
- Centralia
- Chehalis
- Chehalis Village
- Chelan
- Cheney
- Cherry Grove
- Chewelah
- Chinook
- Clarkston
- Cle Elum
- Clear Lake
- Clyde Hill
- Cohassett Beach
- Colfax
- College Place
- Colville
- Conconully
- Concrete
- Connell