| Acronym | Definition |
|---|
| NAO➣North Atlantic Oscillation |
| NAO➣National Audit Office (UK government) |
| NAO➣Not an Option |
| NAO➣National Astronomical Observatory (Japan) |
| NAO➣Négociation Annuelle Obligatoire (French: Mandatory Annual Negotiation) |
| NAO➣National Applications Office (US DHS) |
| NAO➣New Account Opening (various companies) |
| NAO➣North American Operations |
| NAO➣non-asbestos organic |
| NAO➣National Academy of Opticianry |
| NAO➣New Age Outlaws (wrestling) |
| NAO➣National Authorising Officer (various nations) |
| NAO➣National AHEC (Area Health Education Center) Organization |
| NAO➣Sodium Oxide |
| NAO➣New Anzat Order (Star Wars) |
| NAO➣Natural Atomic Orbital |
| NAO➣Native American Outreach |
| NAO➣Naval Aviation Observer |
| NAO➣Non-Animal Origin |
| NAO➣Nasal Airway Obstruction |
| NAO➣Number Allocation Organisation |
| NAO➣New Associate Orientation (introductory training for new employees) |