| Abbreviation | Definition |
|---|---|
| AAACS | Average Amino Acid Conservation Score |
| ABCA | Ausable Bayfield Conservation Authority |
| ABEC | Animal Behavior Ecology and Conservation |
| ACAP | Agreement on the Conservation of Albatrosses and Petrels |
| ACBK | Association for the Conservation of Biodiversity of Kazakhstan |
| ACC | American Conservation Coalition |
| ACCB | African Congress for Conservation Biology |
| ACCB | Allamakee County Conservation Board |
| ACCB | Angkor Centre for Conservation of Biodiversity |
| ACCB | Audubon County Conservation Board |
| ACCD | Allegheny County Conservation District |
| ACCI | Ape Cognition and Conservation Initiative |
| ACCR | Advisory Committee for Conservation and Restoration |
| ACCRU | Alberta Cooperative Conservation Research Unit |
| ACCS | Alaska Center for Conservation Science |
| ACI | Association for Conservation Information |
| ACPF | Agriculture Conservation Planning Framework |
| ACPU | Advanced Conservation and Protection Unit |
| ACSFP | Alcoa Conservation and Sustainability Fellowship Program |
| ACTN | African Conservation Tillage Network |