| Abbreviation | Definition |
|---|---|
| OCR | Oversized Compact Race |
| ODCR | Oklahoma Dwarf Car Racing |
| ODLM | Ontario Dirt Late Models (Canada) |
| OFRC | Ohio Fair Racing Conference |
| OGT | Olivia Grace Thomas |
| OKR | OutKast Racing |
| OLGR | Office of Liquor, Gaming and Racing |
| OLR | On-Line Racing |
| OLTT | Object Level Tracing Toolkit |
| OMR | Old Man Racing |
| OMR | Online Motor Racing |
| OMR | Orbea Monocoque Race |
| OMRS | Ontario Modifieds Racing Series |
| OPEL | Open, Every, Line. Out, Pass, Every, Line. Over, Prefomence,Every,Line. Over,Pass,Every,Last Ass. |
| ORA | Ontario Racing Association |
| ORC | Offshore Racing Congress |
| ORC | Offshore Racing Council |
| ORC | Ogura Race Clutch |
| ORC | Ogura Racing Clutch |
| ORCA | Online Racing Championship Association |