| Abbreviation | Definition |
|---|---|
| IIRC | Irish Indoor Rowing Championships |
| IJMO | Irish Jesuit Mission Office |
| IKKU | Irish Kenpo Karate Union |
| IKSA | Irish Kite Surfing Association |
| ILDI | Ireland Limited Dublin Ireland |
| IMAG | Irish Mensa Annual Gathering |
| IMASA | Irish Mission Adventist Students Association |
| IMGS | Irish Mapping and GIS Solutions |
| IMLA | Irish Maritime Law Association |
| IMNI | Independent Mechanism for Northern Ireland |
| IMRS | Irish Missionary Resource Service |
| IMSF | Irish Motorsport Support Fund |
| IMSN | Irish Medication Safety Network |
| IMTE | Irish Maritime Transport Economist |
| INAD | Irish National Audit of Dementia |
| INDI | Irish Nutrition and Dietetics Institute |
| INHP | Irish National Heritage Park |
| INJ | Irish Network Japan |
| INOU | Irish National Organisation of the Unemployed |
| INSEP | Irish Network for the Study of Esotericism and Paganism |