- Rackerby
- Rail Road Flat
- Rainbow
- Raisin City
- Ramona
- Rancho Calaveras
- Rancho Cordova
- Rancho Cucamonga
- Rancho Mirage
- Rancho Murieta
- Rancho Palos Verdes
- Rancho Penasquitos
- Rancho San Diego
- Rancho Santa Fe
- Rancho Santa Margarita
- Rancho Tehama Reserve
- Randsburg
- Red Bluff
- Red Corral
- Redcrest
- Redding
- Redlands
- Redondo Beach
- Redway
- Redwood City
- Redwood Shores
- Redwood Valley
- Reedley
- Rialto
- Richfield
- Richgrove
- Richmond
- Richvale
- Ridgecrest
- Ridgemark
- Rio Del Mar
- Rio Dell
- Rio Linda
- Rio Oso
- Rio Vista
- Rio Vista
- Ripley
- Ripon
- River Pines
- Riverbank
- Riverdale
- Riverdale Park
- Riverside
- Robbins
- Rocklin
- Rodeo
- Rodriguez Camp
- Rohnert Park
- Rolling Hills
- Rolling Hills
- Rolling Hills Estates
- Rollingwood
- Romoland
- Rosamond
- Rosedale
- Roseland
- Rosemead
- Rosemont
- Roseville
- Ross
- Rossmoor
- Rough and Ready
- Round Mountain
- Round Valley
- Rowland Heights
- Rubidoux
- Running Springs
- Ruth
- Rutherford
