| NJ | Nagoya Japan
| Others |
| NJ | Nan Jin
| Others |
| NJ | Nash Joint
| Others |
| NJ | National Jewish Medical and Research Center
| Others |
| NJ | National Joke
| Others |
| NJ | Natural Join
| Others |
| NJ | Navy Junior
| Others |
| NJ | Nederlandse Jurisprudentie
| Others |
| NJ | Neighbor Joining
| Others |
| NJ | Neighbour Joining
| Others |
| NJ | Net Jockey
| Others |
| NJ | Neutral Jump
| Others |
| NJ | New Jersey 
| State |
| NJ | New Jerusalem
| Others |
| NJ | Niagara Junction Railway (Canadian Pacific Railway)
| Others |
| NJ | Nice Job
| Others |
| NJ | Nick Johnson, baseball player
| Others |
| NJ | Nikkei Jidosha
| Others |
| NJ | Nils Jonas
| Others |
| NJ | No Jive
| Others |
| NJ | No joke
| Others |
| NJ | No Justice
| Others |
| NJ | Non-Jury
| Others |
| NJ | Norma Jean
| Others |
| NJ | Not Jimmy
| Others |
| NJ | Nut Juice
| Others |
| NJ | The Number Of J
| Others |