- Angelus Oaks (17 Companies)
- Angwin (137 Companies)
- Annapolis (16 Companies)
- Antelope (613 Companies)
- Antioch (4,855 Companies)
- Anza (108 Companies)
- Apple Valley (3,109 Companies)
- Applegate (66 Companies)
- Aptos (1,907 Companies)
- Arbuckle (128 Companies)
- Arcadia (6,470 Companies)
- Arcata (2,119 Companies)
- Arleta (86 Companies)
- Armona (78 Companies)
- Arnold (390 Companies)
- Aromas (113 Companies)
- Arrowbear Lake (1 Company)
- Arrowbear Lk (2 Companies)
- Arrowhead Farms (2 Companies)
- Arroyo Grande (3,226 Companies)
- Artesia (1,991 Companies)
- Artois (13 Companies)
- Arvin (597 Companies)
- Atascadero (2,819 Companies)
- Atherton (320 Companies)
- Atwater (1,665 Companies)
- Atwood (8 Companies)
- Auberry (158 Companies)
- Auburn (6,209 Companies)
- Avalon (306 Companies)
- Avenal (243 Companies)
- Avery (43 Companies)
- Avila Beach (88 Companies)
- Azusa (2,403 Companies)
