ASA
- ASA (automobile)
- ASA Aluminium Body
- ASA carriage control characters
- ASA physical status classification system
- Accessible surface area
- Acetylsalicylic acid
- Acoustical Society of America
- Acrylonitrile styrene acrylate
- Adaptive simulated annealing
- Advanced surface ablation
- Advertising Standards Authority (disambiguation)
- Aeropuertos y Servicios Auxiliares
- African Safari Airways
- African Studies Association
- African Studies Association of the United Kingdom
- Agremiação Sportiva Arapiraquense
- Air transport agreement
- Airline Superintendents Association
- Airservices Australia
- Alandica Shipping Academy
- Alaska Airlines
- Albany Students' Association
- Alexander-Smith Academy
- Alliance Sport Alsace
- Allied States of America
- Allmennaksjeselskap
- Alpha Sigma Alpha
- Amateur Softball Association
- Amateur Swimming Association
- American Samoa
- American Scientific Affiliation
- American Society for Aesthetics
- American Society of Agronomy
- American Society of Anesthesiologists
- American Society of Appraisers
- American Sociological Association
- American Speed Association
- American Sportscasters Association
- American Staffing Association
- American Standards Association
- American Statistical Association
- American Student Assistance
- American Studies Association
- American Synesthesia Association
- Americans for Safe Access
- Anterior spinal artery
- Anti-Soviet agitation
- Antisperm antibodies
- Arabic
- Argininosuccinic aciduria
- Arizona School for the Arts
- Arizona Soccer Association
- Armenian Sisters Academy
- As-salamu alaykum
- Assistant Secretary of the Army
- Association for Social Advancement
- Association for the Study of Abortion
- Association of Scouts of Azerbaijan
- Association of Social Anthropologists
- Association of Southeast Asia
- Astronomical Society of Australia
- Athletics South Africa
- Atlantic Southeast Airlines
- Atlético Sport Aviação
- Auditory scene analysis
- Australian Society of Authors
- Australian Space Agency
- Australian Submarine Agency
- Austrian Service Abroad
- Austrian Studies Association
- Autism Society of America
- Cisco ASA
- District attorney
- Film speed
- Hawaiian Airlines
- United States Adult Soccer Association
- United States Army Security Agency
- Åsa (disambiguation)