| Acronym | Definition |
|---|
| AIO | All in One |
| AIO | Adventures in Odyssey |
| AIO | Assistent in Opleiding |
| AIO | Associazione Italiana Odontoiatri |
| AIO | Audio Input Output |
| AIO | Asynchronous Input Output |
| AIO | Aquittement Input Output |
| AIO | Amerta Indah Otsuka (Indonesia) |
| AIO | Adapt, Improvise, Overcome |
| AIO | Asynchronous Input/Output |
| AIO | Analog Input/Output |
| AIO | Attitudes, Interests, Opinions (market research) |
| AIO | Anthropological Index Online (monthly bibliographic references to over 700 periodicals in the British Museum's Museum of Mankind library) |
| AIO | Activities, Interests and Opinions |
| AIO | Amiga Information Online |
| AIO | Assistant in Opleiding |
| AIO | All in Order (police reports) |
| AIO | Acadia Institute of Oceanography |
| AIO | Air Intelligence Officer |
| AIO | African Insurance Organization (Cameroon) |
| AIO | Arctic Iñupiat Offshore, LLC (Mexico) |
| AIO | Action Information Organization |
| AIO | Australian Imagery Organisation |
| AIO | Arecibo Ionospheric Observatory (Puerto Rico) |
| AIO | Acquisition Integration Office |
| AIO | Air Interdiction Officer |
| AIO | Aerospace Information Operations |
| AIO | Assistant Immigration Officer |
| AIO | Advances In Osteoporosis |
| AIO | Asset Identification Officer (US Air Force) |