ARA
- ARA News
- Aerial rocket artillery
- Alliance for Retired Americans
- Amateur Rowing Association
- Amateurs Radio Algeriens
- Amedeo Rocco Armentano
- American Radio Association
- American Railway Association
- American Rally Association
- American Relief Administration
- Angiotensin II receptor antagonist
- Annual Report
- Anti-Racist Action
- Anti-Racist Alliance
- AppleTalk Remote Access
- Application release automation
- Applied Research Associates
- Ara (disambiguation)
- Arab Rescue Army
- Arachidonic acid
- Arcade and Attica Railroad
- Archives and Records Association
- Armada de la República Argentina
- Armenian Revolutionary Army
- Artistička Radna Akcija
- Aryan Republican Army
- Askaryan Radio Array
- Assets Recovery Agency
- Associate of the Royal Academy
- Athénée Royal d'Auderghem
- Auckland Regional Authority
- Audio Random Access
- Australasian Raptor Association
- Australian Regular Army
- Risk aversion
- Swarm intelligence