| Acronym | Definition |
|---|
| IOA | Indian Olympic Association |
| IOA | Islands of Adventure (Universal Studios theme park) |
| IOA | Institute on Aging (University of North Carolina) |
| IOA | Institute of Acoustics |
| IoA | Institute of Astronomy |
| IOA | International Ozone Association |
| IOA | International Ombudsman Association (Hillsborough, NJ) |
| IOA | International Ostomy Association |
| IOA | Interobserver Agreement (medicine) |
| IOA | Input/Output Adapter |
| IOA | Indiana Optometric Association |
| IOA | Industrial Operations Analyst (GSA job description) |
| IOA | International Oversight Advisory (fictional, TV series Stargate) |
| IOA | Investigators of America |
| IOA | Integrated Operations Architecture (NASA) |
| IOA | Ioannina, Greece - Ioannina (Airport Code) |
| IOA | In Name Of |
| IOA | International Ornithological Association |
| IOA | Input/Output Automaton |
| IOA | Institute of Outdoor Advertising |
| IOA | Integrated Office Accounting |
| IOA | Initial Operational Assessment |
| IOA | International Olympic Athlete (2000 Olympics; now East Timor) |
| IOA | Independent Orbiter Assessment (Space Shuttle) |
| IOA | Independent Operational Assessment |
| IOA | Inductive Output Amplifier |
| IOA | Integrated Operation Architecture (BMS Software, Inc) |
| IOA | Immediate Origination Approach |
| IOA | Instrument Operating Assembly |
| IOA | Incidence of Aggression |
| IOA | Information-Oriented Architecture |
| IOA | Institute of Archaeology (University of California, Los Angeles) |