| Abbreviation | Definition |
|---|---|
| HGS | Helmholtz Graduate School |
| HGS | Hitchin Girls School |
| HGSB | Hough Graduate School of Business |
| HGSCF | Harvard Graduate School Christian Fellowship (Cambridge, MA) |
| HGSE | Harvard Graduate School of Education |
| HGSS | Holmer Green Senior School |
| HGSS | Homantin Government Secondary School |
| HGST | Houston Graduate School of Theology |
| HHCS | Henderson Hammock Charter School |
| HHCS | HOPE for Hyndman Charter School |
| HHCS | Hua Hsing Chinese School |
| HHCS | Huber Heights City Schools |
| HHES | Heathwood Hall Episcopal School |
| HHFS | Hope Hall Foundation School |
| HHHS | Haddon Heights High School |
| HHHS | Hamilton Heights High School |
| HHHS | Harker Heights High School |
| HHHS | Hasbrouck Heights High School |
| HHHS | Hatboro Horsham High School |
| HHHS | Hawkley Hall High School |