| NAO | National Association of Optometrists | 全国验光师协会 |
| NAO | National Audit Office | 国家审计署 |
| NAO | North American Operations | 北美运营 |
| NAO | Nanchong, Mainland China | 中国大陆南充 |
| NAO | Non-Animal Origin | 非动物来源 |
| NAO | New Age Outlaws | 新时代亡命徒 |
| NAO | New Anzat Order (Star Wars) | 新安札特秩序（星球大战） |
| NAO | North American Outreach | 北美外联 |
| NAO | NOAA Administrative Order | NOAA行政命令 |
| NAO | National Audit Office (UK government) | 国家审计署（英国政府） |
| NAO | Nasal Airway Obstruction | 鼻气道阻塞 |
| NAO | New Associate Orientation (introductory training for new employees) | 新员工入职培训（新员工入门培训） |
| NAO | National Astronomical Observatory (Japan) | 日本国家天文台 |
| NAO | Naval Aviation Observer | 海军航空观测员 |
| NAO | Number Allocation Organisation | 编号分配组织 |
| NAO | Sodium Oxide | 氧化钠 |
| NAO | non-asbestos organic | 非石棉有机物 |
| NAO | National Academy of Opticianry | 国家光学学会 |
| NAO | New Age Outlaws (wrestling) | 新时代传奇（摔跤） |
| NAO | Natural Atomic Orbital | 自然原子轨道 |