| Abbreviation | Definition |
|---|---|
| IWFA | Irish Woodworkers for Africa |
| IWLA | Iowa World Language Association |
| IWLA | Izaak Walton League of America |
| IWMI | International Water Management Institute |
| IWMS | Irrigation Water Management Society |
| IWPO | International Whale Protection Organisation |
| IWPR | Institute for Women's Policy Research |
| IWR | Institute of Water Resources |
| IWRC | Indian Water Rights Coalition |
| IWRC | INRA (Inland Northwest Research Alliance) Water Resources Consortium |
| IWRC | International Wildlife Recovery Center |
| IWRC | International Wildlife Rehabilitation Council |
| IWU | Injured Workers United, Inc. |
| IYA | Indian Youth of America |
| IYB | International Youth Brigade |
| IYCB | International Youth Council Bangladesh |
| IYE | International Youth Exchange |
| IYERP | Idaho Youth Education Recycling Partnership |
| IYF | International Youth Foundation |
| IYHF | International Youth Hostel Federation |