| Abbreviation | Definition |
|---|---|
| OREO | Ottawa Region Electric Organization |
| ORM | Other Regulated Material |
| ORP | Optimum Recording Power |
| ORT | Ongoing Reliability Test |
| OS | Operating System |
| OSB | Oriented Strand Board |
| OSBL | OutSide the Battery Limit |
| OSC | Organic Solderability Coating |
| OSD | On-Screen Display |
| OSD | Open Source Device |
| OSD | Oscillator Strength Distribution |
| OSD | Over Sampling Depth |
| OSD | Over-Sampling Depth |
| OSDH | Optical Shubnikhov-DeHaas effect |
| OSE | Orient Semiconductor Electronics |
| OSEE | Open Source Electrical Engineering |
| OSET | Oliver Smith Electric Trials |
| OSI | Open Systems Interconnection |
| OSP | Organic Solderability Preservative |
| OSR | Over-Sampling Ratio |