| A&P | Advertising Promotion |
| A&P | Advertising & Promotion |
| A. C. MOORE ARTS | Arts & Crafts Moore (more) |
| A2C | Association des agences de communication créative |
| AAAA | American Association for Advertising Agencies |
| AAAA | Association of Accredited Advertising Agents |
| AAAA | Antique Advertising Association of America |
| AAAA | American Association of Advertising Agencies |
| AAAM | Association of Advertising Agents of Macau |
| AAAM | Advertising Agencies Association of Myanmar |
| AAAN | Advertising Agencies Association of Nigeria |
| AAAN | Association of Advertising Agencies of Nigeria |
| AAFB | American Advertising Federation of Baltimore |
| AAFN | American Advertising Federation Nashville |
| AAIR | Advertising Arts in Review |
| AAP | Alternative Advertising Possibilities |
| AARB | Alcohol Advertising Review Board |
| ABAC | Atlanta Broadcast Advertising Club |
| ABAC | Alcoholic Beverages Advertising Code |
| ACA | Association of Canadian Advertisers |