| Abbreviation | Definition |
|---|---|
| NSC | National Security Council |
| NSC | National Space Council |
| NSIA | National Security Industrial Association |
| NSIPS | NRL Satellite Image Processing System |
| NSMO | Nederlandsche Stoomvaart Maatschappij Oceaan |
| NSP | Neurological Shellfish Poisoning |
| NSRDB | National Solar Radiation Data Base |
| NSRDC | Naval Ship Research and Development Center |
| NSRS | National Spatial Reference System |
| NSSDC | National Space Science Data Center |
| NTF | National Tidal Facility |
| NTFS | Network of Tropical Fisheries Scientists |
| NTHMP | National Tsunami Hazard Mitigation Program |
| NTIA | National Telecommunications and Information Administration |
| NTIS | National Technical Information Service |
| NTN | National Trends Network |
| NTOU | National Taiwan Ocean University |
| NTWC | National Tsunami Warning Center |
| NUC | Naval Undersea Research and Development Center |
| NURC | National Undersea Research Center |