| Abbreviation | Definition |
|---|---|
| NASCAR | National Associationfor Stock Car Auto Racing |
| NASCAR | National Associatoin for Stock Car Auto Racing |
| NASCAR | National Assosciation of Stock Car Auto Racing |
| NASRA | North American Scooter Racing Association |
| NASRIN | North American Simulcast Racing Information Network |
| NB | No Bracing |
| NBR | No Brakes Racing |
| NBRA | National Boat Racing Association |
| NCRA | National Center for Race Amity |
| NCRA | National Championship Racing Association |
| NDMA | Nacionaline Distancinio Mokymo Asociacija |
| NDMA | North Dakota Motocross Association |
| NDRA | National Dirt Racing Association |
| NDRA | National Drag Racing Association |
| NDRA | Nelson Drag Racing Association |
| NDRA | NOPI Drag Racing Association |
| NDRC | National Drag Racing Circuit |
| NDRD | National Dialogue on Race Day |
| NDRL | National Dirt Racing League |
| NDRL | Nostalgia Drag Racing League |