| Acronym | Definition |
|---|
| NSO | National Statistics Office (Philippines) |
| NSO | National Symphony Orchestra |
| NSO | New Student Orientation |
| NSO | Nashville Symphony Orchestra (Nashville, TN) |
| NSO | National Statistical Office |
| NSO | Novosibirskaya Oblast (Russian federal subject) |
| NSO | Nintendo Switch Online (paid online gaming service) |
| NSO | National Solar Observatory |
| NSO | Nalu Service Object |
| NSO | Names Supporting Organization |
| NSO | Naming Service Object |
| NSO | Nevada Site Office |
| NSO | Nurses Service Organization (liability insurance company) |
| NSO | National Service Officer (Disabled American Veterans) |
| NSO | Northern Spotted Owl |
| NSO | No Such Organization (Vassar University; Poughkeepsie, NY) |
| NSO | Network Security Officer |
| NSO | Nonqualified Stock Option |
| NSO | Nevada Solar One (Boulder City, NV) |
| NSO | Nederlands Studenten Orkest (Dutch: Netherlands Student Orchestra) |
| NSO | Northern Star Online (Minnesota) |
| NSO | Neighbourhood Specialist Officer (UK) |
| NSO | Newfoundland Symphony Orchestra (Canada) |
| NSO | New Store Opening |
| NSO | National Security Office(r) |
| NSO | National Census and Statistics Office (Philippines) |
| NSO | National Sales Organizations |
| NSO | North Sydney Oval |
| NSO | National Socialist Society (political group; Russia) |
| NSO | NATO Standardization Organization |
| NSO | National Safeman's Organization |
| NSO | Numeric Stockage Objective |
| NSO | New Student Outreach |
| NSO | Nonferrous Smelter Order |
| NSO | Network Systems & Operations |
| NSO | Nuclear Safety Officer |
| NSO | Non-Subscriber Order |
| NSO | Non-Skating Official (roller derby) |
| NSO | Natural Spin Orbital(s) |
| NSO | Naval Staff Officer |
| NSO | Non-SIOP Option |
| NSO | Nuclear Safe Orbit |
| NSO | Nuclear Support Office |
| NSO | Navy Subsistence Office |
| NSO | Non-Standard Option |
| NSO | Navy Supply Officer |
| NSO | Non Standard Operation |
| NSO | Neutral Start Output |
| NSO | Non-Streaming Overhead |
| NSO | Nail Solution for Onychomycosis |
| NSO | Normal Sustained Operations |
| NSO | NATO (North Atlantic Treaty Organizations) School Oberammergau (Oberammergau, Germany) |
| NSO | National Support Officer |