| Abbreviation | Definition |
|---|---|
| APPP | Aligning Practice, Policy and Priority |
| APPSA | Atlantic Provinces Political Science Association |
| APR | American Politics Research |
| APRG | American Politics Research Group |
| APRL | American Politics Research Lab |
| APRN | An Phoblacht Republican News |
| APRV | Alianza Popular Regional Valenciana |
| APSA | American Political Science Association |
| APSC | ASEAN Political Security Community |
| APSM | Association of Political Science Majors |
| APSR | American Political Science Review |
| APW | American Politics Workshop |
| AR | A**hole Republicans |
| AR | Antiwar Republican |
| ARAB | Antifaschistische Revolutionäre Aktion Berlin (Antifascist Revolutionary Action Berlin) |
| ARDU | Afar Revolutionary Democratic Union |
| ARF | Armenian Revolutionary Federation |
| ARI | Always Reaching for Independence |
| ARI | Angus Reid Institute |
| ASALA | Armenian Secret Army for the Liberation of Armenia |