| Abbreviation | Definition |
|---|---|
| OCS | Open Control System |
| OCS | Optical Convergence Switch |
| OCV | Open Circuit Voltage |
| OCZ | Output, CMOS levels, Tri-stateable |
| OD | Opal Diffuser |
| OD | Open Drain |
| OD | Outside Diameter |
| ODAPI | Open database Api |
| ODAPI | Open document API |
| ODEC | Old Dominion Electric CooperativePDF |
| ODEON | Online Demand Electronic Order Network |
| ODMR | Optical Detected Magnetic Resonance |
| ODR | Oscillating Disk Rheometer |
| ODS | Ozone-Depleting Substance |
| OEBR | Optical Edge Bead Removal |
| OEC | Oklahoma Electric Cooperative |
| OECD | Organization of Electrical Companies Directorate |
| OED | Opto Electronic Device |
| OEDS | OPERA Electronic Distribution Suite |
| OEE | Optical Entrance Enclosure |