NPA
- .NET Persistence API
- 1-N-Naphthylphthalamic acid
- Deferred prosecution
- N-Propyl-L-arginine
- NPA Satellite Mapping
- Nanopascal
- Nasopharyngeal airway
- National Pacification Army
- National Parks Association (disambiguation)
- National Party of Australia
- National Pasta Association
- National Pawnbrokers Association
- National People's Action
- National People's Ambassadors
- National People's Army
- National Pharmacy Association
- National Physicians Alliance
- National Ploughing Championships
- National Police (disambiguation)
- National Port Authority, Liberia
- National Postdoctoral Association
- National Prescription Administrators
- National Production Authority
- National Prosecuting Authority
- National park authority
- Naval Air Station Pensacola
- Network Printing Alliance
- Network Professional Association
- Neutral Paralympic Athletes at the 2018 Winter Paralympics
- Neutral Paralympic Athletes at the 2024 Summer Paralympics
- New Anticapitalist Party
- New People's Army
- Niemann–Pick disease
- Nigerian Ports Authority
- Nitropropionic acid
- No party affiliation (disambiguation)
- Non-Partisan Association
- Non-Party Affiliate
- Non-performing asset
- Northcoast Preparatory and Performing Arts Academy
- Northern Pacific Airways
- Northland Preparatory Academy
- Norwegian People's Aid
- Note Printing Australia
- Numbering Plan Area
- Polar auxin transport
- Sardar Vallabhbhai Patel National Police Academy
- Transnet National Ports Authority