| Abbreviation | Definition |
|---|---|
| HKIR | Hong Kong International Races |
| HMR | Historic Monoposto Racing |
| HOB | Horace O'Bryant |
| HORC | Hellenic Offshore Racing Club |
| HORL | Hendrick Online Racing League |
| HOTH | Hell On The Humber (Race conducted on the Humber Bridge, near Kingston upon Hull, England) |
| HPR | High Plains Raceway |
| HRC | Honda Racing Company |
| HRC | Honda Racing Corporation |
| HRE | Harvey Racing Engines |
| HRF | Historic Race Finland |
| HRI | Horse Racing Ireland |
| HRMC | Harness Racing Medication Collaborative |
| HRN | Horse Racing Nation |
| HRP | Hepfner Racing Products |
| HRRN | Horse Racing Radio Network |
| HRT | Hispanic Racing Team |
| HRT | Holden Racing Team |
| HRU | Harness Racing Update |
| HRV | Harness Racing Victoria |