| NPO | Natalie Portman Obsessives 
| Others |
| NPO | National Portfolio Organisations
| Others |
| NPO | National Preservation Office
| Others |
| NPO | National Printing Office
| Others |
| NPO | National Productivity Organization
| Others |
| NPO | National Program Office
| Others |
| NPO | National Programme Office
| Others |
| NPO | Native Promise Only
| Others |
| NPO | Naval Pay Office
| Others |
| NPO | Navy Purchasing Office
| Others |
| NPO | Nederlandse Publieke Omroep
| Others |
| NPO | Negative and Positive to Zero
| Others |
| NPO | Neighborhood Patrol Officer
| Others |
| NPO | Neighborhood Police Officer
| Others |
| NPO | Neighborhood Police Officers
| Others |
| NPO | Neighborhood Preservation Ordinance
| Others |
| NPO | Network Performance Objectives
| Others |
| NPO | Network Performance Optimization
| Others |
| NPO | Never Precisely Originated
| Others |
| NPO | New Pacific Order
| Others |
| NPO | New Polar Order
| Others |
| NPO | New Product Offering
| Others |
| NPO | Next Planet Over
| Others |
| NPO | Nicastro Piscopo Ogrin, Attorneys at Law
| Others |
| NPO | Nil Per Os
| Others |
| NPO | Nil Per Os (Nothing By Mouth)
| Others |
| NPO | NNSA Production Office
| Others |
| NPO | No Particular Order
| Others |
| NPO | No Problem Observed
| Others |
| NPO | Non Per Os
| Others |
| NPO | Non Productive Overtime
| Others |
| NPO | Non Profit Organisation
| Others |
| NPO | Non Profit Organisations
| Others |
| NPO | Non Profit Organization
| Others |
| NPO | Non profit organizations
| Others |
| NPO | Non Promt Organisation
| Others |
| NPO | Northern Physicians Organization
| Others |
| NPO | Not for Profit Organization
| Others |
| NPO | Nothing By Mouth (nulla per os)
| Others |
| NPO | Nothing Per Oral
| Others |
| NPO | Nothing Per Orem
| Others |
| NPO | Nu Phunk Operation
| Others |
| NPO | Nurse Practitioners of Oregon
| Others |