| Abbreviation | Definition |
|---|---|
| NIDAS | Naval Interactive Data Analysis System |
| NIDAS | Naval Interactive Display And Analysis System |
| NIFF | Navy Interchange File Format |
| NIFR | Naval Infantry Force Recon |
| NIFR | Naval Information Force Reserve |
| NIKE | Naval Inertial Konfinement Experiment |
| NIOC | Naval Information Operations Command |
| NIP | Naval Intelligence Professionals |
| NIPO | Navy International Programs Office |
| NISC | Naval Information Service Center |
| NISE | Naval Innovative Science and Engineering |
| NISMF | Naval Inactive Ships Maintenance Facility |
| NISMF | Navy Inactive Ship Maintenance Facilities |
| NISMF | Navy Intermediate Ship Maintenance Facility |
| NISMO | Naval Inactive Ship Maintenance Office |
| NIU | Naval Intelligence Unit |
| NJROTC | A Naval Junior Reserves Officers Training Corps |
| NJROTC | Navy Junior Reserve Officer Training Corps |
| NKO | Naval Knowledge Online |
| NKO | Navy Knowledge Online |