| Acronym | Definition |
|---|
| OER | Open Educational Resources |
| OER | Official Exchange Rate |
| OER | Oxygen-Evolution Reaction (energy) |
| OER | Office of Extramural Research (US NIH) |
| OER | Oil Extraction Rate |
| OER | Odakyu Electric Railway (Japan) |
| OER | Office of External Relations (various organizations) |
| OER | Osservatorio Epidemiologico Regionale (Italian: Regional Epidemiological Observatory) |
| OER | Office of Employee Relations (various locations) |
| OER | Oracle Enterprise Repository (software) |
| OER | Office of Educational Research |
| OER | Octet Encoding Rules |
| OER | Optimized Edge Router |
| OER | Office of Emergency Response |
| OER | Officer Evaluation Report |
| OER | Optimized Edge Routing |
| OER | Owners' Equivalent Rent |
| OER | Office of Equal Rights (US FEMA) |
| OER | Operating Expense Ratio |
| OER | Officer Efficiency Report |
| OER | Office of Energy Research |
| OER | Open Ended Response |
| OER | Officer Effectiveness Report |
| OER | Office of Environmental Restoration |
| OER | Operational Electronic Intelligence (ELINT) Requirements (US DoD) |
| OER | Office of Exploratory Research |
| OER | Orange Empire Railway |
| OER | Organizational Efficiency Review |
| OER | Operating Experience Report/Review |
| OER | Odd-Even Rule |
| OER | Order Entry Representative |