| Abbreviation | Definition |
|---|---|
| GRAC | Great Rivers Athletic Conference |
| GSAC | Garden State Athletic Conference |
| GSAC | Golden State Athletic Conference |
| GSAC | Great South Athletic Conference |
| GTAA | Georgia Tech Athletic Association |
| GWAL | Greater Wichita Athletic League |
| GYAT | Go You Athletic Teens |
| HAA | Hamburg Athletic Association |
| HAA | Hampton Athletic Association |
| HAAA | Hempfield Area Athletic Association |
| HAAC | Heart of America Athletic Conference |
| HAAC | Hungarian American Athletic Club |
| HABA | Holliston Athletic Boosters Association |
| HAC | Hockessin Athletic Club |
| HAD | Human Athletic Dance |
| HAF | Hilltopper Athletic Foundation |
| HAVOC | Heightening the Athleticism and Values Of Children |
| HCAC | Heartland Collegiate Athletic Conference |
| HCAL | Honor Charter Athletics League |
| HCAL | Houston Charter Athletics League |