- Acalanes Ridge
- Acampo
- Acton
- Adelanto
- Adin
- Adin-Lookout
- Aerial Acres
- Agoura Hills
- Agoura Hills-Malibu
- Agua Dulce
- Aguanga
- Ahwahnee
- Airport
- Alameda
- Alamo
- Albany
- Albion
- Alderpoint
- Alhambra
- Alhambra Valley
- Aliso Viejo
- Allensworth
- Alondra Park
- Alpaugh
- Alpine
- Alpine Meadows
- Alpine Village
- Alta
- Alta Loma
- Alta Sierra
- Alta Sierra
- Altadena
- Alturas
- Alum Rock
- Alviso
- Amador City
- Amador Pines
- Amboy
- American Canyon
- Amesti
- Anaheim
- Anaheim Hills
- Anaheim-Santa Ana-Garden Grove
- Anderson
- Angels
- Angels Camp
- Angels City
- Angelus Oaks
- Angwin
- Antelope
- Antelope Acres
- Antioch
- Antioch-Pittsburg
- Anza
- Apple Valley
- Applegate
- Aptos
- Aptos Hills-Larkin Valley
- Arbuckle
- Arcadia
- Arcata
- Arden-Arcade
- Arleta
- Armona
- Arnold
- Arnold-West Point
- Aromas
- Arroyo Grande
- Artesia
- Artois
- Arvin
- Arvin-Lamont
- Ashland
- Atascadero
- Atherton
- Atwater
- Auberry
- Auburn
- Auburn Lake Trails
- August
- Avalon
- Avenal
- Avery
- Avila Beach
- Avocado Heights
- Azusa