| Acronym | Definition |
|---|
| BAO | Batman: Arkham Origins (gaming) |
| BAO | Baryon Acoustic Oscillations (cosmology) |
| BAO | Business Analytics and Optimization (IBM) |
| BAO | Basal Acid Output (medical test) |
| BAO | Business Analyst Online (software) |
| BAO | Bundesabgabenordnung (Austria) |
| BAO | Bouche à Oreille (French: Word of Mouth) |
| BAO | Brussels Agentschap voor de Onderneming (Dutch: Brussels Enterprise Agency; Brussels, Belgium) |
| BAO | Behavior Analyst Online (online scientific journals) |
| BAO | Bilateral Affairs Officer (US DoD) |
| BAO | Boulder Atmospheric Observatory |
| BAO | Birmingham AIDS Outreach |
| BAO | Bachelor of Obstetrics |
| BAO | Bloc Américaniste Occidentaliste (French: American Western Bloc) |
| BAO | Bomb Appraisal Officer (US TSA) |
| BAO | Boeing Aerospace Operations |
| BAO | Bruce Artwick Organisation |
| BAO | Best Available Option |
| BAO | Bachelor of the Arts of Obstetrics (UK) |
| BAO | Branch Artery Occlusion |
| BAO | Battalion Ammunition Officer (US Army) |
| BAO | Baikal Astrophysical Observatory (Listvyanka, Russia) |
| BAO | Best Atomic Orbital |
| BAO | Breathing Apparatus Operator (safety) |
| BAO | 2,5-Bis-4-Aminophenyl-1,3,4-Oxadiazole (chemistry) |
| BAO | Bear Artists Online (est. 2008) |
| BAO | Burlington Area Office |
| BAO | Business Administration Officer Committees |