| Abbreviation | Definition |
|---|---|
| OPTASKLINK | Operations Task Link |
| OPTEC | Operational Test and Evaluation Command |
| OPTEMPO | Operating Tempo |
| OPTEMPO | Operations Tempo |
| OPTINT | Optical Intelligence |
| OPTIR | Optical IR Backgrounds |
| OPUS | OSS/PODPS (Observation Support System/Post-Observation Data Processing System) Unified System |
| OPV | Observation Post Vehicle |
| OPW | Objective Personal Weapon |
| OPZONE | Operation Zone |
| OQ | Officers' Quarters |
| OQ | Operational Quantity |
| OQF | Ordnance Quick Firing |
| OQR | Officer Qualification Record |
| OQT | Officer Qualification Testing |
| OR | Official Regulation |
| OR | Operational Readiness |
| OR | Operational Requirement |
| OR | Operations Research |
| OR | Other Rank(S) (NATO) |