IHSAA
| Acronym | Definition |
|---|---|
| IHSAA | Indiana High School Athletic Association (Indianapolis, IN; est. 1903) |
| IHSAA | Idaho High School Activities Association (Boise, ID) |
| IHSAA | Iowa High School Athletic Association (also seen as IAHSAA) |
| IHSAA | Ithaca High School Alumni Association (est. 2003; Ithaca, NY) |