| Abbreviation | Definition |
|---|---|
| IYS | Impact Youth Services |
| IYS | Inala Youth Service |
| IYS | Indiana Youth Soccer |
| IYS | Individualized Youth Services |
| IYS | Institute for Youth Success |
| IYS | Integral Youth Services |
| IYS | Integrated Youth Services |
| IYS | International Youth Service |
| IYS | Iowa Youth Survey |
| IYS | Iowa Youth Symposium |
| IYS | ISKCON Youth Services |
| IYSS | Integrated Youth Support Service |
| IYSS | Integrated Youth Support Services |
| IYSS | Intensive Youth Support Service |
| IYT | Intermission Youth Theatre |
| IYW | Institute for Youth Work |
| IYWN | International Youth Workers Network |
| IYY | International Year of Youth |
| IYY | International Youth Year |
| IYYAD | International Youth and Young Adult Department |