| Acronym | Definition |
|---|
| SAO | Saco (Amtrak station code; Saco, ME) |
| SAO | Sao Paulo (Capital City; Brazil) |
| SAO | Sword Art Online (Japanese light novel series) |
| SAO | Student Activities Office |
| SAO | State Auditor's Office |
| SAO | Software Association of Oregon (Portland, OR) |
| SAO | Student Affairs Office |
| SAO | Service-Oriented Architecture (software) |
| SAO | Smithsonian Astrophysical Observatory |
| SAO | South Atlantic Ocean |
| SAO | Study Abroad Office |
| SAO | Share An Opportunity (various organizations) |
| SAO | State Attorney's Office |
| SAO | Shin Angyo Onshi (gaming) |
| SAO | Sheffield Assay Office (UK) |
| SAO | Standard Application Online (school admissions) |
| SAO | Session-At-Once (CD burning mode) |
| SAO | Special Astrophysical Observatory (Zelenchuksky region, Russian Federation) |
| SAO | State Accounting Office (various locations) |
| SAO | Session at Once |
| SAO | Short Acting Opioid (medication) |
| SAO | Sexually Acting Out (psychology) |
| SAO | Senior Administration Official |
| SAO | Security Advisory Opinion |
| SAO | Statement of Account (finance) |
| SAO | School Administrative Officer (Australia) |
| SAO | Stay Away Order (judicial decree) |
| SAO | Security Assistance Organization |
| SAO | Ski Area Operations (Colorado) |
| SAO | Semi-Annual Oscillation |
| SAO | Southeast Asian Ovalocytosis |
| SAO | Student Alumni Organization (various schools) |
| SAO | Student Activities Organization (various schools) |
| SAO | Salvation Army Officer |
| SAO | Security Assistance Office/Officer (US DoD) |
| SAO | Sport Alliance of Ontario |
| SAO | Selected Attack Option (US DoD) |
| SAO | La Société des Antiquaires de l'Ouest (French: Antiquarian Society of the West) |
| SAO | Single Association Object |
| SAO | Special Artificer, Optical (US Navy) |
| SAO | State Approving Officer (US FEMA) |
| SAO | Southern Association for Oncology |
| SAO | Stacy Adams Outdoors (shoes) |
| SAO | Sport Automobile Océan (French car racing) |
| SAO | Stratford Athletic Organization |
| SAO | Side A Only (band) |
| SAO | Situations d'Apprentissage Ouvertes (French: Open Learning Situations) |
| SAO | Special Activities Office |
| SAO | Stichting voor Alzheimer Onderzoek |
| SAO | Smartasses Online |
| SAO | Safety Assessment Office |
| SAO | Systematic Analysis of Operations |
| SAO | Sailplane Air Operations (European Union Aviation Safety Agency) |
| SAO | San Francisco Area Office |
| SAO | Subsequent Address with One signal (CCS #7 & ITU-T) |
| SAO | Staff Action Officer |
| SAO | Survivor's Assistance Officer |
| SAO | Special Access Office (various organizations) |
| SAO | Student Ambulance Officer |
| SAO | Senior Acquisition Officer |
| SAO | Serviciul Angajatori Online |
| SAO | Site Activation Officer |
| SAO | Sandia Area Office |
| SAO | Sonobuoy Acoustic Operator |
| SAO | Summary Alarm Outputs (Ciena) |
| SAO | Substance Abuse Officer |
| SAO | System Analysis Office |
| SAO | System Acquisition Officer |
| SAO | Support Air Observation |