| I/OU | Input/Output Unit  
| Technology |
| IOU | I Owe Unto
| Others |
| IOU | I Owe You
| Others |
| IOU | Idle Online Universe
| Others |
| IOU | Ile Ouen, New Caledonia
| Others |
| IOU | Illinois Owes Us
| Others |
| IOU | Images of Us
| Others |
| IOU | Improved Outback Upgrade
| Others |
| IOU | Independent Operating Unit
| Others |
| IOU | Indian Ocean University
| Others |
| IOU | Inform Open Unite
| Others |
| IOU | Innovative Original Unique
| Others |
| IOU | Input Output Unit
| Others |
| IOU | Inside Our Universe
| Others |
| IOU | Integrated Optics for Undergraduates
| Others |
| IOU | Intensive therapy Observation Unit
| Others |
| IOU | Intensive Therapy Observation Unit.
| Others |
| IOU | Interdependent Occupational Unit
| Others |
| IOU | Internal Office Use
| Others |
| IOU | International Octel Users
| Others |
| IOU | International Open University
| Others |
| IOU | Internet of You
| Others |
| IOU | Intersection over Union
| Others |
| IOU | Investor Owned Utilities
| Others |
| IOU | Investor Owned Utility
| Business, Finance |
| IOU | Investor-Owned Utility
| Others |
| IOU | Inward Outward and Upward
| Others |
| IOU | Iodine Oxygen and Uranium
| Others |
| IOU | IOS on Unix
| Others |
| IOU | Iron And Oreminers United
| Others |
| IOU | Is Owed Unto ....
| Others |
| IOU | Islamic Online University
| Others |