| Abbreviation | Definition |
|---|---|
| NJA | National Jumping Association |
| NJA | New Jersey Amateur Golf Tournament |
| NJAC | New Jersey Athletic Conference |
| NJB | National Junior Basketball |
| NJB | North Jersey Brigade |
| NJCL | National Junior Classical League |
| NJD | New Jersey Devils Hockey Team |
| NJHC | New Jersey HardCore |
| NJL | National Jyhad League |
| NJL | Nordic Jet Line |
| NJN | NEW JERSEY NETS Hockey Team |
| NJPW | New Japan Pro-Wrestling |
| NJS | New Jersey Stars Soccer Team |
| NJS | Nihon Jitensha Shinkōkai (Japan Bicycle Promotion Association) |
| NJSC | New Jersey Ski Council |
| NJSF | New Japan Sports Federation |
| NJSL | Northwest/Jackson Soccer League |
| NK | Nogometni Klub |
| NKA | Northbrook Kids Baseball |
| NKB | Northbrook Kids Baseball |