| 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 |