| Abbreviation | Definition |
|---|---|
| NNP | Number Needed to Protect |
| NNPT | Nuclear Non-Profliferation Treaty |
| NNPTC | Naval Nuclear Power Training Command |
| NNS | Newport Naval Station |
| NNSS | Navy Navigational Satellite System |
| NNTP | Nuclear Network Timing Packet |
| NNWC | Naval Network Warfare Command |
| NO | Native Officer (colonial India) |
| NO | Number |
| NOACT | Navy Overseas Air Cargo Terminal |
| NOB | Northern Operating Base |
| NOC | Network Operations Center |
| NOC | Non-Operational Cell |
| NOCMIS | Network Operations Center Management Information System |
| NOCMIS | NOC Management Information System |
| NOCONTRACT | Not Releasable to Contractors or Consultants |
| NOCRLF | No Carriage Return/Line Feed |
| NOD | (N)ightvision (O)ptical (or Observation) (D)evice |
| NODIS | No Distribution |
| NOE | Nap-Of-the-Earth |