OUN
| Acronym | Definition |
|---|---|
| OUN | Organization of Ukrainian Nationalists |
| OUN | Order Unit |
| OUN | Organizacija Ujedinjenih Nacija (Serbian: United Nations) |
| OUN | Occasional Use Notices (UK; gambling law) |
| OUN | Organizatsiya Ukrainskikh Natsionalistiv (Ukrainian: Organization of Ukrainian Nationalists) |
| OUN | Oslo University Notation (Oslo, Norway) |