C
- Cabin Creek
- Cactus
- Camano
- Camas
- Camden
- Camp Discovery
- Canby
- Canterwood
- Canyon Park
- Cap Sante
- Carbonado
- Carlisle
- Carlmar
- Carlsborg
- Carlton
- Carlyon Beach
- Carnation
- Carrolls
- Carrs Corner
- Carson
- Cascade Park East
- Cascade Park West
- Cascade Valley
- Cashmere
- Cashup
- Casino Corner
- Castle Rock
- Cathan
- Cathcart
- Cathlamet
- Cavalero Corner
- Cedar
- Cedar Crossing
- Cedardale
- Cedar Falls
- Cedar Grove
- Cedarhurst
- Cedar Mountain
- Cedarville
- Cedarville
- Cedarville
- Cedonia
- Centerville
- Central Ferry
- Centralia
- Central Park
- Central Valley
- Chaffee
- Chain Hill
- Chambers
- Chard
- Charter Oak
- Chattaroy
- Chehalis
- Chehalis Village
- Chelan
- Chelan Falls
- Chelatchie
- Cheney
- Cherokee Bay Park
- Cherry Grove
- Chesaw
- Chester
- Cheviot
- Chewelah
- Chico
- Chillowist
- Chimacum
- Chinook
- Chiwaukum
- Chopaka
- Christopher
- Chuckanut
- Chumstick
- Cicero
- Cinebar
- Cispus
- Clallam Bay
- Claquato
- Clarkston
- Classet
- Clay City
- Clayton
- Clear Lake
- Clearview
- Clearwater
- Cle Elum
- Cleveland
- Cliffdell
- Cliffs
- Climax
- Clinton
- Clipper
- Cloverland
- Clyde
- Clyde Hill
- Coal Creek
- Coal Creek
- Coalfield
- Cohassett
- Cohassett Beach
- Cokedale
- Colbert
- Colby
- Coles Corner
- Colfax
- College Place
- Colton
- Columbia
- Colville
- Colville Agency
- Colvos
- Conconully
- Concrete
- Connell
- Conway
- Cook
- Copalis Beach
- Copalis Crossing
- Coppei
- Cora
- Cordell
- Corfu
- Corkindale
- Cornet
- Cosmopolis
- Cottage Lake
- Cougar
- Cougar Valley
- Coulee City
- Coulee Dam
- Country Homes
- Coupeville
- Covada
- Cove
- Covello
- Coville
- Covington
- Cowiche
- Cowlitz
- Coyle
- Cozy Nook
- Crabtree
- Craige
- Crane
- Crater
- Crawford
- Creston
- Creswell Heights
- Croker
- Cromwell
- Crosby
- Croskey
- Crown Hill
- Crystal Springs
- Cumberland
- Cunningham
- Curlew
- Curry
- Curtis
- Cusick
- Custer
- Custer