| AIO | Activities Innovation and Opinions 
| Others |
| AIO | Activities Interests and Opinions
| Others |
| AIO | Activities Interests Opinions
| Others |
| AIO | Activities, Interests, and Opinions
| Others |
| AIO | Adventures In Odyessy
| Others |
| AIO | Adventures in Odyssey
| Others |
| AIO | Advertising Institutions And Operations
| Others |
| AIO | Aerospace Industries Organization
| Others |
| AIO | Aikido Instructors Organization
| Others |
| AIO | Akamai Internet Observatory
| Others |
| AIO | All in One
| Others |
| AIO | All In Ones
| Others |
| AIO | All Is Ok
| Others |
| AIO | All-In-One
| Others |
| AIO | Alternative Income Opportunities
| Others |
| AIO | American Indian Opportunities
| Others |
| AIO | American Institute of Organbuilders
| Others |
| AIO | Americans for Indian Opportunity
| Others |
| AIO | Amsoil Injector Oil
| Others |
| AIO | Analog Input/Output
| Others |
| AIO | APL file transfer format file
| Others |
| AIO | Applied Industrial Optics
| Others |
| AIO | Aquittement Input Output
| Others |
| AIO | Assistent In Opleiding
| Others |
| AIO | Associates In Ophthalmology
| Others |
| AIO | Asynchronous I O
| Others |
| AIO | Asynchronous Input Output
| Others |
| AIO | ATCCS (Army Tactical Command and Control System) Integration Office
| Others |
| AIO | Atlantic Municipal Airport
| Others |
| AIO | Attic Inscriptions Online
| Others |
| AIO | Audio Input Output
| Others |
| AIO | Australian Informatics Olympiad
| Others |
| AIO | Automotive Investment Organization
| Others |