| Abbreviation | Definition |
|---|---|
| ILSY | Independent Living Services for Youth |
| ILYC | I Live Youth Church |
| IMYA | International Multifaith Youth Assembly |
| IMYF | Indonesia Muslim Youth Forum |
| IMYF | Indonesian Maritime Youth Festival |
| IMYT | Inverclyde Musical Youth Theatre |
| ISTY | I Still Love You |
| ISY | In School Youth |
| ISYS | Information System for Youth Services |
| ISYS | Institute for the Study of Youth Sports |
| ITY | Ieuenctid Tysul Youth |
| ITY | Isaiah Temple Youth |
| IUDD | Igreja Universal dos Dons de Deus |
| IUY | Illinois United for Youth |
| IUYWG | International Union Youth Working Group |
| IVY | I- Incredible V- VictoryY- of the Youth |
| IVY | Incredible Vocal Youth |
| IVY | Interreg Volunteer Youth |
| IVYS | Inland Valley Youth Symphony |
| IYA | IITA Youth Agripreneurs |