AA

**AA**, **Aa**, **Double A**, or **Double-A** may refer to:

## Arts, entertainment and media 
* ''America's Army*, a 2002 computer game published by the U.S. Army
* *Ancient Anguish*, a computer game in existence since 1992
* Aa!, a J-Pop musical group
* Double-A (band), stylised as AA, South Korean boy band
* *Aa* (album), a 2016 album by Baauer
* AA (song), a 2021 single by Walker Hayes
* Ace Attorney, a series of video games developed by Capcom.
*AA Films, an Indian film distribution company
*AA Book (disambiguation)
*AA, the production code for the 1966 *Doctor Who* serial *The Savages''

## Brands, organizations and enterprises 
* Alcoholics Anonymous, an international fellowship dedicated to helping alcoholics peer to peer in sobriety
* A. A. Arms, a defunct firearms manufacturer
* Aerolíneas Argentinas, an Argentine airline (logo used to consist of two A's)
* Air Asia, an Asian multinational low cost carrier
* Alcoa, an American aluminum-producing company (stock symbol AA)
* American Airlines, major American full-service airline (IATA airline code, logo used to consist of two A’s)
* Anadolu Agency, a state-run press agency in Turkey
* Audio-Animatronics, used at the Disney Parks
* Academia de Artes, Mexico
* Amalgamated Association of Iron and Steel Workers, a former union in the United States
* Andecha Astur, an Asturian nationalist party
* Architectural Association School of Architecture, London, United Kingdom
* Astrological Association of Great Britain, London, United Kingdom
* *Auswärtiges Amt*, the Foreign Office of Germany
* Danish Association of Architects (*Akademisk Arkitektforening*)
* The AA (formerly The Automobile Association), a British motoring organization
* AA Ireland, an Irish  automotive services company
* AA Motoring Trust, a former British road safety charity operated by The AA that was merged to form the IAM Motoring Trust

## Philosophy and religion 
* A∴A∴, a spiritual organization created in 1907 by Aleister Crowley
* Abhisamayalankara, or Abhisamaya-alaṅkāra, a Mahayana Buddhist text
* Augustinians of the Assumption, a congregation of Catholic religious (priests and brothers)
* Statue of A'a from Rurutu, a wooden fertility-god sculpture from the Pacific island of Rurutu
* "A is A", an expression of the law of identity: each thing is identical with itself

## Language 
* aa, Latin-script digraph used in the orthographies of Dutch, Finnish and other languages
* aa, representation of letter Å in several Scandinavian languages
* aa, a romanization of Arabic letter alif ا
* Ꜳ, an orthographic ligature
* Afar language (ISO 639-1 language code aa)
* Aa (Bengali), a Bengali letter

## Measurements
* AA, a bra size
* AA, a width in shoe sizes
* AA battery size

## Nature 
* *Aa* (plant), a genus of orchid
* *Aa* (snail), a subgenus of snail 
* ʻAʻā or aa, a form of lava
* A term for "river" in German hydronymy, see Aach (toponymy)

## People 
* Aa (surname), a Scandinavian surname, including a list of people with this name
* Van der Aa (surname), a Dutch surname, including a list of people with this name
* Aa (architect), an architect in ancient Egypt
* Anthony Armstrong (writer) (1897–1972), Anglo-Canadian writer who used the pseudonym A.A.

## Places
* Aa, Estonia, a village and beach in Estonia
* Aa, Indonesia, a populated place in the South Sulawesi province of Indonesia
* Ann Arbor, a city in Michigan, United States of America

## Rivers 
### Belgium 
*Aa (Nete), a river in the province of Antwerp, which joins the Nete

### France 
*Aa (France), a river in northern France

### Germany 
*Aabach (Afte), formerly called the Große Aa, a river in North Rhine-Westphalia
*Aa (Möhne), a river in North Rhine-Westphalia
*Aa (Nethe), a river in North Rhine-Westphalia
*Aa (Werre), a river in North Rhine-Westphalia
*Bocholter Aa, a river in North Rhine-Westphalia
*Dreierwalder Aa, a river in North Rhine-Westphalia
*Kleine Aa (Aabach), a tributary of the Aabach in North Rhine-Westphalia
*Große Aa, a tributary of the Ems in Lower Saxony
*Große Aa (Aabach), a tributary of the Aabach in North Rhine-Westphalia
*Münstersche Aa, a river in North Rhine-Westphalia
*Schaler Aa, a river in Lower Saxony and North Rhine-Westphalia
*Speller Aa, a river in Lower Saxony and North Rhine-Westphalia
*Steinfurter Aa, a river in North Rhine-Westphalia

### Netherlands 
*Aa (Meuse), a river in North Brabant, which joins the Dommel to form the Dieze
*Aa of Weerijs, a river in North Brabant, which joins the Mark at Breda
*Drentsche Aa, a river in Drenthe and Groningen
*Mussel Aa, a river in Westerwolde, Groningen
* Ruiten Aa, a river in Westerwolde, Groningen
*Westerwoldsche Aa, a river near Oudeschans, Groningen

### Switzerland 
*Aabach (Aare), a tributary of the Aare in canton of Aargau
*Aabach (Greifensee), or Ustermer Aa, a river in canton of Zürich
*Aabach (Obersee), a tributary of Obersee (Zürichsee), in canton of St. Gallen
*Aabach (Seetal), a river in the cantons of Lucerne and Aargau, runs through Lake Hallwyl
*Chli Aa (Sempachersee), a tributary of Lake Sempach in the canton of Lucerne
*Engelberger Aa, a river in the cantons of Obwalden and Nidwalden, tributary of Lake Lucerne
*Gross Aa (Sempachersee), a tributary of Lake Sempach in the canton of Lucerne
*Mönchaltorfer Aa, a tributary of Greifensee in canton of Zürich
*Sarner Aa (river), a river in Obwalden, tributary of Lake Lucerne

### Latvia 
*Gauja, a river in Latvia, formerly known as *Livländische Aa*
*Lielupe, a river in Latvia, formerly known as *Kurländische Aa*

## Science and technology 
* AA amyloidosis, a form of amyloidosis related to serum amyloid A
* Amino acid, often abbreviated *aa* when indicating positions in a peptide sequence (e.g., aa 120–150)
* Antiandrogen, a drug which blocks the effects of androgens
* Aplastic anemia, a rare disease
* Arachidonic acid, a polyunsaturated fatty acid
* Advanced Architecture, original name of Amiga Advanced Graphics Architecture
* Anti-aliasing, various techniques for mitigating certain signal processing artifacts
* Atlas Autocode, a computer programming language
* AA, a proprietary digital audio format of Audible.com
* Authoritative Answer, in DNS, a flag for a query answer
* AA postulate of Euclidean geometry
* Anti-aircraft, in military use
* Abampere (aA), the CGS unit of current
* Attoampere (aA), a unit of electric current equal to 10−18 Ampere
* AA tree, named after Arne Andersson
* AA, the abbreviation for azidoazide azide
* AppArmor

## Sports 
* Double-A (baseball) or Class AA, a classification level in Minor League Baseball since 1912
* American Association (1882–1891), a professional baseball league in the United States from 1882 to 1891
* American Association (1902–1997), a professional baseball league in the United States from 1902 to 1962 and 1969 to 1997
* American Association of Professional Baseball, a professional baseball league in the United States and Canada since 2006
* Athletics Australia, national sporting organisation in Australia

## Transportation 
* AA Highway, a state highway in Northern Kentucky
* Ann Arbor Railroad (1895–1976), a defunct railroad in Ohio and Michigan
* Ann Arbor Railroad (1988), a railroad operating in Ohio and Michigan
* *K* line, a defunct line on the New York City Subway, formerly called "AA"
* NZR AA class, a locomotive class operated by the New Zealand Railways Department

## Other uses 
* African American, as a cultural identity
* Asian Aerospace, an airshow in Asia
* Associate of Arts, an academic degree
* European Union Association Agreement
* Postal abbreviation for United States armed forces in the Americas
* Japanese internet slang for Shift JIS art
* Internet slang for ASCII Art

## Related pages 
* A (disambiguation)