AB

• American Bandstand, a music-performance television show
• Analecta Bollandiana, an academic journal on Christian hagiography
• Ancienne Belgique, a concert hall in Brussels, Belgium

Businesses

Manufacturing companies

• A & B High Performance Firearms, a defunct sporting firearms manufacturer
• Allen-Bradley, a brand of industrial control products, manufactured by Rockwell Automation
• Anheuser-Busch, a brewing company

Media companies

• AB Groupe, a French broadcasting group
• Activision Blizzard, an American video game holding company
• American Biograph, a former motion picture company

Transportation companies

• AB Airlines, a defunct British airline
• Air Berlin (former IATA airline code AB), a former airline operating 1978–2017
• Appenzell Railways (Appenzeller Bahnen), abbreviated AB
• Bonza (IATA code AB), an Australian airline

Other companies

• AB Bank, a commercial bank in Bangladesh
• Alderson Broaddus University, formerly Alderson-Broaddus College, a private university in West Virginia, US
• Alfa-Beta Vassilopoulos, a Greek supermarket chain
• AllianceBernstein (New York Stock Exchange Symbol AB), a US-based asset management firm

Business terminology

• Akcinė bendrovė, Lithuanian equivalent of an S.A. corporation
• Aktiebolag, Swedish for "corporation", similar to AG, Ltd or Inc.

• Abkhaz language (ISO 639-1 language code ab), a Northwest Caucasian language spoken mostly by the Abkhaz people
• Ab (cuneiform), a written syllable
• Ab (Semitic), a Semitic word for "father"
• ab, a Welsh patronymic prefix
• Āb, a Persian word, derived from Ap (water), the Vedic Sanskti term for water

• Able seaman, a civilian occupation
• Able seaman (rank), a naval rank
• Airman basic, the lowest rank in the US Air Force

• Afrikaner Broederbond, a South African secret society from 1918 to 1994
• Aryan Brotherhood, an American gang

• Āb or Anzab-e Olya, a village in Iran
• AB postcode area, UK, including Aberdeen, Scotland
• AB, the WMO country code of Albania
• AB, the postal abbreviation and ISO 3166 suffix for Alberta, a province in Canada
• Air Base, used by the United States Air Force for overseas bases
• AB, used in vehicle registrations for Aschaffenburg, Germany
• AB, used in vehicle registrations for the Special Region of Yogyakarta, Indonesia

Chemistry

• Alabamine, a former name of the element astatine
• Albite, a feldspar mineral
• Ammonia borane, a chemical compound
• Antibonding (a.b.), used to describe the character of orbitals in atomic and molecular electronic structure

Medicine

• AB blood, a blood type in the ABO blood group system
• AB toxin, Type III toxin secreted by some pathogenic bacteria
• Antibody (medical abbreviation)
• Rectus abdominis muscle (common name abs), a paired stomach muscle

Other uses in science and technology

• AB (star catalogue)
• Aggregate base, a kind of material used in construction
• AB Class amplifier, a classification of electric amplifier
• Category of abelian groups (Ab), in mathematics
• ApacheBench, a command line tool for Apache HTTP Server

• Ab (Egyptian heart-soul concept), a concept in ancient Egyptian religion
• Pirkei Avot (Hebrew: פִּרְקֵי אָבוֹת, romanized: pirqē aḇoṯ / Pirke Aboth /..., lit. 'Chapters of the [Fore]fathers'), a compilation from the Mishnaic period (abbreviation "Ab.")
• Aitareya Brahmana, an ancient Indian collection of hymns
• Ab or Av (month), Hebrew: אָב, fifth in the Hebrew calendar, and eleventh in the Tishri-years
• Ab (Classical Mandaic: ࡀࡁ) or Aria (month), seventh in the Mandaean calendar

• Akademisk Boldklub, a Danish professional football club
• Argja Bóltfelag, a Faroese association football club
• Aviron Bayonnais, French rugby union club
• At bat, in baseball statistics

• Borneo Airways Limited, IATA airline designator AB (to 1965)
• NZR Ab class, a New Zealand steam locomotive
• Armed boarding steamer, used by the UK during World War I
• Crane ship (AB) (US Navy hull classification symbol AB)

• Ab (given name), a short form of Albert (or occasionally Abraham or Abbott)
• AB de Villiers (born 1984), South African middle order batsman and wicket-keeper
• Adrien Broner (born 1989), American Boxer, nicknamed AB
• Allan Border (born 1955), Australian cricketer, nicknamed A.B.
• Antonio Brown (born 1988), American football player, nicknamed AB

• AB, a South Australian dish similar to a Halal snack pack
• Adult baby, a person who practices paraphilic infantilism
• Bachelor of Arts (Latin: Artium baccalaureus)
• Assembly Bill, a type of legislation in the US
• AB (game), a guessing game similar to Mastermind