| Abbreviation | Definition |
|---|---|
| HXS | Hawaiian Xtreme Sports |
| IAAC | Inter-collegiate Athletics Advisory Committee |
| IAAF | International Amateur Athletics Federation |
| IAAF | International Association of Athletics Federations |
| IABA | Irish Amateur Boxing Association |
| IABO | Inter-collegiate Athletics Business Office |
| IACC | International America's Cup Class |
| IAFA | Irish American Football Association |
| IAHA | Indianapolis Amateur Hockey Association |
| IASE | International Association of Sports Economists |
| IASI | International Association for Sports Information |
| IASM | Institute For Arthroscopy And Sports Medicine |
| IATA | International Advanced Training Association |
| IAUP | International Association of Underwater Polo |
| IAWC | Indoor Archery World Cup |
| IAWT | In Arsene We Trust |
| IBA | International Basketball Association |
| IBA | Iron Butt Association |
| IBB | Intentional Base on Balls |
| IBBA | Irving Boys Baseball Association |