A9, A.9, A09, A 9 or A-9 may refer to:
Science ATC code A09 Digestives, including enzymes, a subgroup of the Anatomical Therapeutic Chemical Classification System Biolimus A9, an immunosuppressant British NVC community A9, the Potamogeton natans community, one of the aquatic communities of the British National Vegetation Classification HLA-A9, a broad antigen serogroup of Human MHC HLA-A Subfamily A9, a Rhodopsin-like receptors subfamily
Technology A9home, a small form factor computer A9.com, a website and search engine by Amazon.com Apple A9, a 64-bit system on a chip (SoC) designed by Apple Inc. Hanlin eReader A9, an ebook reader
Aviation Breda A.9, a 1928 Italian biplane trainer aircraft CallAir A-9 Quail, an agricultural aircraft Georgian Airways's IATA code Lockheed A-9, a ground attack aircraft based on the Lockheed YP-24 fighter prototype Northrop YA-9, a ground-attack aircraft that competed with the Fairchild Republic A-10 Thunderbolt II
Military A9, a military staff designation in the continental staff system A 9, a Swedish artillery regiment A9, a model of German Aggregate Series Rocket from World War II Cruiser Mk I (A9), a British tank
Music A9 (band), a Japanese rock band originally named Alice Nine A-9, a Gibson mandolin guitar model
Other uses A9 (classification), an amputee sport classification A9 road, in several countries; see List of A9 roads A9, an international ISO 216 paper size standard (37×52 mm) A-9 Vigilance, a fictional starfighter from the Star Wars universe Arrows A9, a 1986 British racing car , a 1988 diving support vessel for the Royal New Zealand Navy HMS A9, an A-class submarine of the Royal Navy Réti Opening or A09, a chess opening A9 TV, a Turkish television station Chery Fulwin A9, a mid-size sedan
See also Grumman Gooseor Grumman OA-9, "Goose" amphibious aircraft in USAAC service α9 (disambiguation) 9A (disambiguation)