IYO
| Acronym | Definition |
|---|---|
| IYO | International Year of the Ocean |
| IYO | In Your Opinion |
| IYO | Inconspicuous Yellow Office (Sheffield University Architecture School UK) |
| IYO | Italian-American Youth Organization (various locations) |
| IYO | Indian Youth Organisation (Delhi, India) |
| IYO | Indianapolis Youth Orchestra |