| NACAB | : | National Association of Citizens’ Advice Bureaux |
| NACILA | : | National Council of Indian Library Association |
| NACL | : | National Advisory Commission on Libraries (USA) |
| NACO | : | National Coordinated Cataloguing Operations |
| NACSIS | : | National Centre for Scientific Information Systems |
| NAG | : | National Acquisitions Group |
| NAI | : | National Archives of India |
| NAL | : | National Aeronautical Laboratory |
| NAL | : | National Agricultural Library (USA) |
| NAPC | : | National Programme for Acquisition and Cataloguing |
| NARA | : | National Archives and Records Administration |
| NASA | : | National Aeronautical and Space Administration |
| NASSDOC | : | National Social Science Documentation Center |
| NATIS | : | National Information System |
| NBC | : | National Broadcasting Corporation |
| NBLC | : | Nederlands Bibliotheek en Lektuur Centrum [Dutch Centre for Public Library Literature] |
| NBS | : | National Bibliographic Service |
| NBT | : | National Book Trust |
| NCCP | : | National Coordinated Cataloguing Programme |
| NCIP | : | North American Collection Inventory Project |
| NCL | : | National Central Library |
| NCL | : | National Chemical Laboratory |
| NCSI | : | National Centre for Science Information |
| NDLP | : | Netherlands Library Development Project |
| NEPHIS | : | Nested Phrase Indexing System |
| NGO | : | Non-Governmental Organization |
| NHS | : | National Health Service |
| NIC | : | National Informatics Center |
| NICDAP | : | National Information Centre for Drug and Pharmaceuticals |
| NICFOS | : | National Information Centre for Chemistry and Chemical Technology |
| NICLAI | : | National Information Centre for Leather and Allied Industry |
| NICMAP | : | National Information Centre for Machine Tools and Allied Products |
| NICNET | : | National Informatic Centre Network |
| NIDOC | : | National Information and Documentation Centre |
| NIFOR | : | National Information Service |
| NII | : | National Institute of Immunology |
| NILA | : | North India Library Association |
| NIP | : | National Information Policy |
| NISIET | : | National Institute of Small Industry Extension Training |
| NISO | : | National Information Standards Organization |
| NISS | : | National Social Science Information System |
| NISSAT | : | National Information System for Science and Technology |
| NLB | : | National Library for the Blind |
| NLB | : | National Library of Bangladesh |
| NLG | : | National Libraries Group |
| NLLST | : | National Lending Library for Science and Technology |
| NLM | : | National Library of Medicine |
| NLSFBPH | : | National Library Service for the Blind and Physically Handicapped |
| NML | : | National Medical Library |
| NNLM | : | National Network for Libraries in Medicine |
| NORDBOK | : | Nordic Literature and Library Committee |
| NORDINFO | : | Nordic Committee on Scientific Information and Documentation |
| NOSP | : | Nordic Union Catalogue of Scientific Periodicals |
| NREN | : | National Research and Education Network |
| NSA | : | National Sound Archive |
| NSDD | : | National Security Decision Directive |
| NSF | : | National Science Foundation |
| NSTP | : | New Straits Times Publications |
| NTA | : | National Telecommunications Agency |
| NTC | : | National Translation Centre |
| NTE | : | Network Terminating Equipment |
| NTIA | : | National Telecommunications and Information Administration |
| NTIS | : | National Technical Information Service |
| NUC | : | National Union Catalog |
| NUCMC | : | National Union Catalog of Manuscript Collections |
| NUCSSI | : | National Union Catalogue of Scientific Serials in India |
| NVQ | : | National Vocational Qualification |
| NWICO | : | New World Information and Communication Order |
| NYSILL | : | New York State Inter Library Loan Network |
| NYT | : | New York Times |