| Abbreviation | Definition |
|---|---|
| OSRM | Office of Standard Reference Materials |
| OSS | Object Services Standard |
| OSV | Offset Scan Voting |
| OT | Optical Transient |
| OT | Overload Time |
| OTA | Operational Transconductance Amplifier |
| OTA | Operational Transistor Amplifier |
| OTC | Output Transformer Coupled |
| OTIS | Optional Transponder Installation Saddle |
| OTL | Output Transformer Loss |
| OTM | Optical Translation Measurement |
| OTPROM | One Time Programmable Read Only Memory |
| OTU | One Time Unit |
| OTU | Optical Test Unit |
| OTU | Optimally Transmissible Unit |
| OUV | Over/Under Voltage |
| OV | Output Voltage |
| OVA | Optical Variable Attenuator |
| OVCO | Overvoltage Cutout |
| OVD | Outside Vapor Deposition |