A3

• A3 regulatory sequence, a sequence for the insulin gene • Adenosine A3 receptor, a human gene • Annexin A3, a human gene • ATC code A03 Drugs for functional gastrointestinal disorders, a subgroup of the Anatomical Therapeutic Chemical Classification System • Brachydactyly type A3, a disease • British NVC community A3 (Spirodela polyrhiza - Hydrocharis morsus-ranae community), a British Isles plants community • Gibberellin A3, a plant hormone • HLA-A3, a Human MHC Serotype HLA-A • Subfamily A3, a rhodopsin-like receptors subfamily • Urea transporter A3, a trans-membrane protein ==Games==

• A3!, a Japanese video game and multimedia franchise • A3 - Assault on the Aerie of the Slave Lords, a 1981 module for the Dungeons & Dragons fantasy role-playing game • Alpha Trion, as the former name of this character from the Transformers Series • Bird's Opening (A03), in chess, by the Encyclopaedia of Chess Openings code ==Music==

• A3, a musical note, the A below Middle C • Alabama 3, a band known as A3 in the U.S. to avoid confusion with the country group Alabama • A-3, a Yamaha musical instrument product ==Sports==

• A3 (classification), an amputee sport classification • A3 Champions Cup, a club football tournament also known as the East Asian Champions Cup • Arrows A3, a 1980 racing car • A3, a climbing grade ==Vehicles==

• A-3 lifeboat, a 1947 lifeboat for carrying by the SB-29 Superfortress • Abrial A-3 Oricou, a French touring aircraft designed in 1927 • Audi A3, a model of automobile • Aussat (Optus) A3, a 1987 Australian telecommunication satellite • Bavarian A III, an 1851 German steam locomotive model • Chery A3, a compact car • LNER Gresley Classes A1 and A3, a Pacific locomotive class designed by Sir Nigel Gresley • SP&S Class A3, a 1914 steam locomotives class ==Weapons and military==

• A-3 Falcon, a variant of the Curtiss Falcon, an attack aircraft manufactured by the Curtiss Aircraft Company • A-3 Skywarrior, a strategic bomber manufactured by Douglas Aircraft Company • AUG A3, a variant of the Austrian Steyr AUG rifle • Fokker A.III, a 1915 armed version of the Fokker M.5 aircraft • HMS A3, a British A-class submarine of the Royal Navy • Kampfgeschwader 200, from its historic Geschwaderkennung code with the Luftwaffe in World War II • Polaris A-3 missile, an American submarine-launched missile • Wendes Artillery Regiment, a former Swedish Army artillery regiment, by designation • A3, the staff designation for air force headquarters staff concerned with operations • A3 Air Operations Branch, of the Joint Force Air Component Headquarters UK • USS Grampus (SS-4), a Plunger-class submarine of the United States Navy • Aggregate 3, the 3rd design in the Aggregate family of rockets, precursor to the V-2 rocket, developed by the Germans during World War II ==Other uses==

• A3, an example of a root system with numerous physical and geometrical applications • A-3 visa, a document given to employees of A-1 and A-2 Visa Holders who are representing a foreign government inside the U.S. • A3, the code for permission to use specific land or premises for restaurants and cafés in town and country planning in the United Kingdom • A3 roads, in several countries • A-003, the fourth abort test of the Apollo spacecraft • Biu-Mandara A.3 languages, an Afro-Asiatic family of languages spoken in Cameroon and Nigeria • Comet A3 also known as C/2023 A3 (Tsuchinshan–ATLAS) • Cowon A3, an audio media player • Aegean Airlines, by IATA code • Tonga, by aircraft registration code • ARITH-MATIC, as the former name for this programming language • "Agora! Anarchy! Action!", a slogan for Agorism taken from the New Libertarian Manifesto by Samuel Edward Konkin III • A3 problem solving, a structured problem solving and continuous improvement approach, first employed at Toyota • Samsung Galaxy A3, a smartphone manufactured by Samsung Electronics • Samsung Galaxy A03, a smartphone manufactured by Samsung Electronics • A³ (A-cubed), an Airbus start-up in the Silicon Valley • A3 (TV channel), an Algerian public national television channel also known as Thalitha TV • RED A03, an aircraft diesel engine by German company Red Aviation GmbH • Zeolite A-3, a potassium-type molecular sieve also known as 3A. • Lely Astronaut A3, the third version of the Astronaut robot manufactured by Lely ==See also==