| Abbreviation | Definition |
|---|---|
| ISCA | International Sports Conditioning Association |
| ISCI | Irish Sports Coaches Institute |
| ISCW | Italian Sports Club of Werribee |
| ISD | Icon Sports Division |
| ISD | Integrated Sports Development |
| ISDO | International Self Defense Organization |
| ISF | International Sports Federation |
| ISG | Innovative Sports Group |
| ISH | Irish Sport Horse |
| ISI | Ice Skating Institute |
| ISI | Illinois Swimming, Inc. |
| ISL | Icehockey Super League |
| ISL | International Sparring League |
| ISL | Irvine Swim League |
| ISLE | Integrated Soccer Learning Environment |
| ISLT | Institut Supérieur Logistique et Transports |
| ISMC | International Ski Mountaineering Competition |
| ISMC | International Snowmobile Media Council |
| ISOA | Illinois Sports Owners Association |
| ISOL | Indoor Sports Of the Lowcountry |