AB
- ab – (s) Abkhaz language (ISO 639-1 code)
- AB
- (i) Able Seaman (both the rank and the occupation)
- (s) Alberta (postal symbol)
- ABA
- (i) Adriatic Basketball Association
- American Bar Association
- American Basketball Association
- American Beverage Association
- American Bicycle Association
- American Birding Association
- Australian Broadcasting Authority
- ABB – (i) ASEA Brown Boveri (Swiss-Swedish multinational company)
- ABBA – (a) Agnetha, Benny, Björn, Anni-Frid (Swedish pop group)
- ABC
- (i) abstinence, be faithful, condoms
- Active Body Control
- airway, breathing, circulation (see CPR)
- Alcoholic Beverage Commission
- alien big cat
- always be careful
- American Bird Conservancy
- American-born Chinese
- American Broadcasting Company
- anti-lock brake controller
- Associated British Corporation
- Atanasoff–Berry Computer
- Atlantic Baptist College
- atomic, biological, chemical (see NBC)
- Australian Broadcasting Corporation
- ABCA
- (i) American, British and Canadian Armies (originally)
- Army Bureau of Current Affairs
- ABCS – (i) (U.S.) Army Battle Command System
- ABET – (a) Accreditation Board for Engineering and Technology
- ABFIST – (i) Advanced Bradley Full Crew Interactive Skills Trainer
- ABGI – (i) Addington-Barker Group International
- ABIN – (a) Agência Brasileira de Inteligência (Brazilian Intelligence Agency)
- abk – (s) Abkhaz language (ISO 639-2 code)
- ABL – (i) American Basketball League
- ABLE – (a) AirBorne Law Enforcement (police air support unit)
- ABM – (i) anti-ballistic missile – Asynchronous Balanced Mode – automated banking machine
- ABMC – (i) American Battle Monuments Commission
- ABN – (i) Australian Business Number (a number issued by the Australian government as registration of a business and used for taxation purposes)
- ABPI – (i) Association of the British Pharmaceutical Industry
- ABRSM – (a) Associated Board of the Royal Schools of Music
- ABS
- (i) acrylonitrile butadiene styrene
- anti-lock braking system
- ABSA – (a) Amalgamated Banks of South Africa ("ab-sa")
- ABSTRIPS – (p) abstraction-based STRIPS
- ABW – (s) Aruba (ISO 3166 trigram)
Read more about this topic: List Of Acronyms And Initialisms: A