| Abbreviation | Definition |
|---|---|
| NION | Not In Our Name |
| NIPC | National Infrastructure Protection Center |
| NIPR | National Intellectual Property Rights |
| NIS | Newly Independent States |
| NISCC | National Infrastructure Security Coordination Centre |
| NISP | National Industry Staffing Patterns |
| NISTIR | National Institute of Standards and Technology Interagency Report |
| NITS | National Institute of Technology And Standards |
| NIV | Non-Immigrant Visa |
| NKPA | No Known Party Affiliation |
| NKVD | Narodny Komissariat Vnutrennih Del |
| NLC | National Liaison Committee |
| NLE | National Library of Education |
| NLI | National Leadership Institute |
| NLIC | National Lead Information Center |
| NLNA | Natural Landmarks and Natural Areas |
| NLRB | National Labor Relations Board |
| NLRD | National Labor Relations Board |
| NLS | National Language Standard |
| NLS | National Leadership Seminar |