| Abbreviation | Definition |
|---|---|
| NNE | Naval Networking Environment |
| NNIU | Norwegian Naval Independent Unit |
| NNL | Naval Nuclear Laboratory |
| NNOA | National Naval Officers Association |
| NNPI | Naval Nuclear Propulsion Information |
| NNS | Nigerian Naval Ship |
| NNS | Nigerian Navy ship |
| NNS | Norfolk Naval Shipyard |
| NNSS | Nigerian Navy Secondary School |
| NNTO | Nigerian Navy Transformation Office |
| NO | Navy Oscar |
| NOAP | Naval Ocean Analysis and Prediction |
| NOB | Naval Operating Base |
| NOB | Naval Order of Battle |
| NOC | Naval Oceanographic Command |
| NOD | Naval Ordinance Department |
| NOFS | Naval Observatory Flagstaff Station |
| NOL | Naval Ordiance Labs |
| NOL | Navy Ortega Lakeshore |
| NOM | Naval Order marines |