| Acronym | Definition |
|---|
| REO | Real Estate Owned |
| REO | Range Estimate Object |
| REO | Ratio of Error Object |
| REO | Radial Error Offset |
| REO | Region Error Option |
| REO | Result Evaluation Object |
| REO | Resident Evil: Outbreak (video game) |
| REO | Research Electro-Optics, Inc. (Boulder, CO) |
| REO | Ransom Eli Olds (automobile manufacturer and namesake of the Oldsmobile and Reo brands; origin for band REO Speedwagon) |
| REO | Rare Earth Oxide |
| REO | Renewable Energy Objective (various locations) |
| REO | Regional Education Office (various locations) |
| REO | Regional Ecosystem Office |
| REO | Regional Environmental Office |
| REO | Regional Embassy Office (US State Department) |
| REO | Regional Ecumenical Organization |
| REO | Repair Engineering Order (aerospace) |
| REO | Respiratory Enteric Orphan Virus |
| REO | Reseau Educatif de l'Ontario (French) |
| REO | Radar Electro-Optical |
| REO | Radio Electronics Officer |
| REO | Research Enterprise Office (Malaysia) |
| REO | Residual Efficient Organization |
| REO | Race Equality Officer |
| REO | Resource Optimizer |
| REO | Regional Economic Organisation |
| REO | Receiver Eye Opening (ANSI) |
| REO | Readiness Engineering Office/Officer |
| REO | Radiated Emissions Test |