| Abbreviation | Definition |
|---|---|
| IC | Internationalized Cocconuts |
| ICA | International Car Association |
| ICCC | International Council of Corvette Clubs |
| ICHF | International Craft Hobby Fair |
| ICSG | International Society of Guatemala Collectors (stamp collecting) |
| ICWG | International Car Wash Guild |
| IDC | Intellectual Discussion Club |
| IDC | Intercultural Discovery Club |
| IDCC | Internet Directory of Camera Collectors |
| IDCX | International Dish Cloth eXchange crocheting club |
| IDK | Internet Development Kit |
| IDMC | Ilkley and District Motor Club |
| IDMS | Iowa Donkey and Mule Society |
| IFC | IMX Fan Club |
| IFO | Indoor Flying Object |
| IGN | In Game Name |
| IGSX | International Granny/Square eXchange crocheting club |
| IHSS | International Humic Substances Society |
| IIS | Infinity International Society |
| ILD | International Lolita Day |