| OP | Operation |
| OPE | Operation |
| NOP | No Operation |
| OM | Operation Mobilisation |
| OR | Operation Research |
| O&M | Operation and Maintenance |
| IOP | Internal Operation |
| OSO | Overscan Operation |
| ROP | RISC Operation |
| ROS | Remote Operation Service |
| ZOO | Zone Operation Organisation |
| OAM | Operation, Administration, Maintenance |
| OBV | Operation Black Vote London, http://www.obv.org.uk |
| OCK | Operation Control Key [engl.] |
| USO | UNIX Software Operation |
| VSO | Variable Speed Operation |
| OMAP | Operation and Maintenance Part |
| OMC | Operation and Maintenance Center |
| SIO | Simultaneous Interface Operation |
| NOC | Network Operation Center |
| FIDO | Fog Investigation Dispersal Operation |
| FLOP | Floating Point Operation |
| PUO | Prohibited User Operation |
| SCO | Santa Cruz Operation, Inc. |
| MOP | Maintenance Operation Protocol [DEC] |
| MRO | Multi-Region Operation |
| CO | Close / Open Operation [engl.] Schaltungen ohne Schaltspiel |
| OSSO | Open Source Solutions Operation [HP] |
| WOLF | Weak Signal Operation for Low Frequency |
| OPDU | Operation Protocol Data Units |
| SPOOL | Simultaneous Peripherals Operation On Line |
| OMPF | Operation and Maintenance Processor Frame |
| AOM | Administration, Operation and Maintenance [engl.] Verwaltung, Betrieb und Instandhaltung, Unternehmensaufgaben |
| AOS | Algebraic Operation System [engl.] Logiksystem von Taschenrechnern |
| ATO | Automatic Train Operation [engl.] Automatische Betriebsdurchführungs-Steuerung bei Bahnen |
| BOS | Basic Operation System [engl.] Computer-Betriebssystem |
| CWMIO | Cisco WAN Manager Installation & Operation |
| ESOC | European Space Operation Centre |
| EUFOR-Althea | EU Military Operation in Bosnia and Herzegovina |
| FSMO | Flexible Single Master Operation |
| ILO | Individual Load Operation [engl.] |
| OCL | Operator/Operation Control Language |
| OECD | Organisation for Economic Co-operation and Development Organisation für wirtschaftliche Zusammenarbeit und Entwicklung |
| OMCR | Operation and Maintenance Center Radio |
| OMCS | Operation and Maintenance Center Switch |
| IMSO | Integrated Micro Systems Operation [Intel] |
| ATOM | Advanced Terminal for Operation and Maintenance [engl.] |
| OMUP | Operation and Maintenance User Part [engl.] |
| CECIMO | European Committee for Co-operation of the Machine Tool Industries |