| Abbreviation | Definition |
|---|---|
| IUBB | Indiana University Basketball |
| IUF | International Unicycling Federation |
| IUF | International Unreal Federation |
| IVC | Inter Varsity Club |
| IVDA | Imperial Valley Desert Aquatics |
| IVHL | Internet Virtual Hockey League |
| IVV | Internationaler VolkssportVerband |
| IWA | Imaginary Wrestling Alliance |
| IWA | International Wrestling Association |
| IWA | Internet Wrestling Alliance |
| IWAC | In With A Chance |
| IWAU | Independent Wrestling Association Unlimited |
| IWC | Intermountain Weavers Conference |
| IWC | International Wrestling Council |
| IWC | Internet Wrestling Community |
| IWE | International Wrestling Entertainment |
| IWF | Internet Wrestling Federation |
| IWGP | International Wrestling Grand Prix |
| IWO | Internal Wrestling Organization |
| IWO | Internet Wrestling Organization |