| N | Nationalist; Navigating Duties; North |
| NA | National Academician (America) |
| NAAFI | Navy, Army and Air Force Institutes |
| NAAS | National Agricultural Advisory Service |
| NAB | National Advisory Body for Public Sector Higher Education |
| NACAB | National Association of Citizens' Advice Bureaux |
| NACETT | National Advisory Council for Education and Training Targets |
| NACF | National Art-Collections Fund |
| NACRO | National Association for the Care and Resettlement of Offenders |
| NAG | National Agriculture Centre |
| NAHA | National Association of Health Authorities |
| Nat/l | National |
| Natl | Natural |
| NATO | North Atlantic Treaty Organisation |
| NB | New Brunswick; Nebraska |
| NBC | National Book Council (later NBL); National Broadcasting Company (US) |
| NC | National Certificate; North Carolina |
| NCA | National Certificate of Agriculture |
| NCB | National Coal Board |
| NCC | National Computing Centre; Nature Conservancy Council; National Consumer Council |
| NCCL | National Council for Civil Liberties |
| NCH | National Children's Homes |
| NCLC | National Council of Labour Colleges |
| NCVO | National Council for Voluntary Organisations |
| ND | North Dakota |
| NDA | National Diploma in Agriculture |
| NDD | National Diploma in Dairying; National Diploma in Design |
| NE | North-east |
| NEB | National Enterprise Board |
| NEC | National Executive Committee |
| NEDC | National Economic Development Council; North East Development Council |
| NEL | National Engineering Laboratory |
| NERC | Natural Environment Research Council |
| NFER | National Foundation for Educational Research |
| NFHA | National Federation of Housing Associations |
| NFS | National Fire Service |
| NFT | National Film Theatre |
| NFU | National Farmers' Union |
| NGO | Non-Governmental Organisation(s) |
| NH | New Hampshire |
| NHS | National Health Service |
| NI | Northern Ireland; Native Infantry |
| NICG | Nationalised Industries Chairmen's Group |
| NIESR | National Institute of Economic and Social Research |
| NJ | New Jersey |
| NM | New Mexico |
| Northants | Northamptonshire |
| Notts | Nottinghamshire |
| NP | Notary Public |
| NR | North Riding |
| NRA | National Rifle Association; National Recovery Administration (US); National Rivers Authority |
| NRD | National Registered Designer |
| NRDC | National Research Development Corporation |
| NRR | Northern Rhodesia Regiment |
| ns | Graduate of Royal Naval Staff College, Greenwich |
| NSM | Non-Stipendiary Minister |
| NSPCC | National Society for the Prevention of Cruelty to Children |
| NSRA | National Small-bore Rifle Association |
| NSW | New South Wales |
| NT | New Testament; Northern Territory (Australia); National Theatre; National Trust |
| NUI | National University of Ireland |
| NUJ | National Union of Journalists |
| NUM | National Union of Mineworkers |
| NUMAST | National Union of Marine, Aviation and Shipping Transport Officers |
| NUPE | National Union of Public Employees |
| NUR | National Union of Railwaymen |
| NUS | National Union of Students |
| NUTG | National Union of Townswomen's Guilds |
| NUU | New University of Ulster |
| NV | Nevada |
| NW | North-west |
| NWF | North West Frontier |
| NWFP | North-West Frontier Province |
| NWP | North-Western Province |
| NY | New York |
| NYC | New York City |
| NZ | New Zealand |
| NZEF | New Zealand Expeditionary Force |