UIO
| Acronym | Definition |
|---|---|
| UIO | Universitetet I Oslo |
| UIO | User Mode Input Output |
| UIO | Universal Input Output |
| UIO | Ungdom I Oppdrag (Youth with a Mission, Norway) |
| UIO | Units in Operation |
| UIO | Universal IO |
| UIO | Unit Information Officer |
| UIO | Quito, Ecuador - Marisca (Airport Code) |
| UIO | Unfunded Investment Opportunity |