Not to be confused with
A0 (A followed by a zero).
AO, aO, Ao, or ao may refer to:
Look up
ao,
Ao, or
AO in Wiktionary, the free dictionary.
- Ao, Estonia, village in Väike-Maarja Parish, Lääne-Viru County, Estonia
- Ao Line, commuter railway line in Hyōgo Prefecture, Japan
- Ao River (Fujian), in China
- Ao Station, railway station in the city of Ono, Hyōgo Prefecture, Japan
- Aodu, capital of Shang dynasty, near Zhengzhou
- Aoshima, Ehime, island in Japan
- Aoshima, Miyazaki, island in Japan
- Angola (ISO 3166-1 alpha-2 code AO)
- AO (originally American Optical Company) eyeglass lenses, a brand now merged with Carl Zeiss Vision
- AO Foundation (originally Arbeitsgemeinschaft für Osteosynthesefragen), a non-profit organisation dedicated to the treatment of trauma and disorders of the musculoskeletal system
- AO Racing, an American sports car racing team
- AO World, a UK retailer of household appliances trading under the brand name ao.com
- Aktsionernoye Obschestvo or Aktsionernoye Obshchestvo (акционерное общество), a type of Russian corporate entity; see open joint-stock company
- Athletics Ontario, formally Ontario Track and Field Association (OTAF)
- Australian Airlines (IATA code AO)
- (697402) Ao, a main-belt asteroid
- .ao, top-level Internet domain code for Angola
- Adaptive optics, an astronomical imaging technology
- Ambient occlusion, a shading method in computer graphics
- AMSAT-OSCAR, a satellite naming convention
- Applied Optics, scientific journal published by the Optical Society of America (OSA)
- Arctic oscillation, a climate pattern
- Atomic orbital, in physics and chemistry
- Ao, the atomic symbol for the misidentified chemical element Ausenium.
- Acridine orange, a fluorescent dye
- Authorship obfuscation, a privacy technique