| Acronym | Definition |
|---|
| ESO➣European Southern Observatory |
| ESO➣Elder Scrolls Online (gaming) |
| ESO➣Educación Secundaria Obligatoria (Spain: compulsory secondary education) |
| ESO➣European Organisation for Astronomical Research in the Southern Hemisphere |
| ESO➣Ether Saga Online (gaming) |
| ESO➣Engineering Services Outsourcing |
| ESO➣Employee Stock Option |
| ESO➣Edmonton Symphony Orchestra (Canada) |
| ESO➣Elgin Symphony Orchestra (Elgin, IL) |
| ESO➣Enseñanza Secundaria Obligatoria (Spain Eeducational system) |
| ESO➣Esophagectomy (surgical procedure) |
| ESO➣École Supérieure d'Ostéopathie (French: Graduate School of Osteopathy) |
| ESO➣European School of Oncology |
| ESO➣English Symphony Orchestra |
| ESO➣Emegency Service Officer (various organizations) |
| ESO➣Educational Services Office(r) |
| ESO➣Essential Skills Ontario (Ontario, Canada) |
| ESO➣Executive Support Officer (various locations) |
| ESO➣Executive Stock Option |
| ESO➣Emergency Service Operations |
| ESO➣Ensemble Studios Online |
| ESO➣Equipment Smarter than Operator |
| ESO➣East Side Office |
| ESO➣Environment Society of Oman |
| ESO➣Extended Sexual Orgasm |
| ESO➣Ecord Science Operator |
| ESO➣Electrical Safety Office |
| ESO➣External Security Organization (Hezbollah) |
| ESO➣Equipment Superior to Operator |
| ESO➣European Standardisation Organisation |
| ESO➣Electronic Sales Order |
| ESO➣Extended Security Option |
| ESO➣Event Services Office (various schools) |
| ESO➣Entrepreneurial Support Organization (various organizations) |
| ESO➣Environmental Science Officer |
| ESO➣Ecological Services Outsourcing (Italy) |
| ESO➣East Side Oakland (California) |
| ESO➣Explosives Safety Officer |
| ESO➣Enterprise Service Optimization |
| ESO➣Electronics Supply Office |
| ESO➣Enligt Senare Order (Swedish: until further orders) |
| ESO➣Emergency Security Option(s) |
| ESO➣Emergency Service Override |
| ESO➣European Settlements Office (banking) |
| ESO➣Estimated Sign Off |
| ESO➣Emergency Support Office |
| ESO➣Engine Shutdown Override |
| ESO➣Expanded Service Option (tape format for packaging software upgrades applied to IBM mainframe systems) |
| ESO➣Electronic Supply Officer |
| ESO➣Engage Standard Order |
| ESO➣External Signaling Option |
| ESO➣Equal Selection Opportunities |
| ESO➣Environmental Services Operations |
| ESO➣Evil Shop Owner |