| Name | Phone | Category |
| AAA - California State Automobile Association | 650-321-0470 | Travel Services |
| Absolute Mortgage Banking | 650-493-3600 | Mortgage |
| Access Land Development Services, Inc. | 650-325-9681 | Real Estate |
| ACE Capital Group | 650-364-3330 | Financial Services |
| Achievekids | 650-494-1200 | Health Services |
| Acterra: Action for a Sustainable Earth | 650-962-9876 | Environment |
| Address Beauty at Beau Visage | 650-321-2200 | Beauty Salons & Services |
| Adecco Employment Services | 650-324-2771 | Staffing Services |
| Adecco Employment Services, Foster City | 650-350-1308 | Staffing Services |
| Adfigo Marketing | 650-361-8006 | Marketing and Communications |
| Adolescent Counseling Services | 650-424-0852 | Community & Human Services |
| AH-HA Associates | 650-630-1795 | Business to Business Resources |
| Alain Pinel Realtors | 650-323-1111 | Real Estate |
| Albert L. Schultz Jewish Community Center | 650-493-9400 | Community & Human Services |
| Alhouse King Keller Williams Realty | 650-354-1100 | Real Estate |
| All Care Plus, Inc. | 650-424-0204 | Health Services |
| All Saints' Episcopal Church and Community Center | 650-322-4528 | Churches |
| Alliance Credit Union | 800-232-8669 | Financial Services |
| Allied Arts Guild | 650-322-2405 | Entertainment and Arts |
| Allstate - Patrick Leland Ins. Agcy | 650-473-5146 | Insurance Services |
| Allstate Insurance | 650-322-5191 | Insurance Services |
| Alta Mesa Memorial Park | 650-493-1041 | Cemeteries |
| Ambiance Interiors, Inc. | 650-494-0161 | Furniture & Accessories |
| American Association of University Women | | Associations, Clubs & Organizations |
| American Cancer Society, Santa Clara County Unit | 408-688-0108 | Health Services |
| American Express Travel Services | 650-327-3711 | Travel Services |
| American Printing & Copy, Inc. | 650-325-2322 | Business to Business Resources |
| American Red Cross, Palo Alto Area Chapter | 650-688-0426 | Community & Human Services |
| American Self Storage | 650-325-8609 | Moving & Storage |
| America's Marketing Department | 650-327-3300 | Marketing and Communications |
| John Amezcua | 650-855-7515 | |
| Ami Laws, MD., Inc. | 650-325-3200 | Physicians |
| Andronico's Market | 510-559-2817 | Grocers & Markets |
| Inge Angiletta Agent, Alain Pinel Realtors | 650-323-1111 | Real Estate |
| Anne Cribbs & Company | 650-856-3200 | Marketing and Communications |
| AP Review Group | 408-739-1501 | Business to Business Resources |
| Argonaut Mortgage Inc. | 650-322-0110 | Mortgage |
| Assemblymember Ira Ruskin | 650-691-2121 | Community & Government |
| Association for Senior Day Health | 650-327-8825 | Associations, Clubs & Organizations |
| AT&T | 415-778-1221 | Telecommunications |
| Atherton Plastic Surgery Center | 650-363-0300 | Health Services |
| Adam Atito, Agent, Keller Williams Realty | 650-320-8095 | Real Estate |
| Avenidas | 650-289-5400 | Community & Human Services |