| Abbreviation | Definition |
|---|---|
| ABWF | American Battered Women Foundation |
| ABWT | Ansar Burney Welfare Trust (Pakistan) |
| AC | Administration Committee |
| AC | Archaeological Conservancy |
| ACA | Adult Children Anonymous |
| ACA | Adult Children of Alcoholics |
| ACA | African Climate Alliance |
| ACA | Alley Cat Allies |
| ACA | American Camp Association |
| ACA | Amputee Coalition of America |
| ACA | Animal Charities of America |
| ACA | Asia Children's Assistance, LTD. |
| ACA | Association of Chinese Americans |
| ACAF | Asian Canadian Artists Fund |
| ACAF | Aureos Central American Fund |
| ACAI | Angelcare Children's Aid International |
| ACAIS | American Camping Association Illinois Section |
| ACAIS | Association for Commonwealth Amnesty International Sections |
| ACANET | American Canoe Association Network |
| ACAP | Alberta Coalition Against Poverty |