| Acronym | Definition |
|---|
| NPN | National Phenology Network (University of Wisconsin-Milwaukee) |
| NPN | Newport News (Amtrak station code; Newport News, VA) |
| NPN | No Purchase Necessary |
| NPN | Notes Public Network |
| NPN | Negative Positive Negative |
| NPN | Natural Product Number |
| NPN | National Performance Network (New Orleans, LA) |
| NPN | Newport News (Virginia) |
| NPN | Nonprotein Nitrogen |
| NPN | New Party Nippon (political party; Japan) |
| NPN | New Plan Network |
| NPN | National Prevention Network |
| NPN | National Petroleum News (magazine) |
| NPN | National Producer Number (insurance) |
| NPN | Negative-Positive-Negative (transistor) |
| NPN | National Party of Nigeria |
| NPN | National Provider Network |
| NPN | NOAA Profiler Network (National Oceanic & Atmospheric Administration) |
| NPN | No Part Number |
| NPN | Nature Photographers Network |
| NPN | No Point Necessary (forum) |
| NPN | Non-Performing Note |
| NPN | Neighborhoods Partnership Network (New Orleans, LA) |
| NPN | National Prayer Network |
| NPN | New Parents Network (Tucson, AZ) |
| NPN | National Peer Network |
| NPN | Natural Parents Network (London, UK) |
| NPN | Neuropathic Pain Network |
| NPN | New Public Network (Ascend) |
| NPN | National Professionals Network |
| NPN | Nashville Publishers Network (Nashville, TN) |
| NPN | Notepager Net |
| NPN | Nederlands Pensioen- en Beleggingsnieuws |
| NPN | National Purchasing Network (Mechanicsburg, PA) |
| NPN | National Particulate Network |
| NPN | Nä Pua No'eau (Center for Gifted and Talented Native Hawaiian Children) |
| NPN | North Pole Network |
| NPN | National Poultry News |
| NPN | National Physician Network |