| Acronym | Definition |
|---|
| SAO | Sao Paulo (Capital City; Brazil) |
| SAO | Smithsonian Astrophysical Observatory |
| SAO | Student Activities Office |
| SAO | Session-At-Once (CD burning mode) |
| SAO | State Auditor's Office |
| SAO | Student Affairs Office |
| SAO | State Attorney's Office |
| SAO | Special Astrophysical Observatory (Zelenchuksky region, Russian Federation) |
| SAO | Study Abroad Office |
| SAO | Software Association of Oregon (Portland, OR) |
| SAO | Senior Administration Official |
| SAO | Security Assistance Organization |
| SAO | Security Advisory Opinion |
| SAO | Semi-Annual Oscillation |
| SAO | Southeast Asian Ovalocytosis |
| SAO | Sport Alliance of Ontario |
| SAO | Salvation Army Officer |
| SAO | Single Association Object |
| SAO | Southern Association for Oncology |
| SAO | Stacy Adams Outdoors (shoes) |
| SAO | Stratford Athletic Organization |
| SAO | Side A Only (band) |
| SAO | Special Activities Office |
| SAO | San Francisco Area Office |
| SAO | security assistance office/officer (US DoD) |
| SAO | Staff Action Officer |
| SAO | selected attack option (US DoD) |
| SAO | Stichting voor Alzheimer Onderzoek |
| SAO | Smartasses Online |
| SAO | Safety Assessment Office |
| SAO | Systematic Analysis of Operations |
| SAO | Senior Acquisition Officer |
| SAO | Subsequent Address with One signal (CCS #7 & ITU-T) |
| SAO | Survivor's Assistance Officer |
| SAO | Site Activation Officer |
| SAO | Serviciul Angajatori Online |
| SAO | Student Ambulance Officer |
| SAO | Sonobuoy Acoustic Operator |
| SAO | Substance Abuse Officer |
| SAO | Summary Alarm Outputs (Ciena) |
| SAO | Sandia Area Office |
| SAO | System Analysis Office |
| SAO | System Acquisition Officer |
| SAO | Support Air Observation |