| opassande förslag | improper suggestion |
| opasslig | indisposed |
| opastöriserad | unpasteurized |
| Opatija | Opatija |
| OPC | OLE for process control |
| OPEC | OPEC |
| Opel | Opel |
| Opel Antara | Opel Antara |
| Opel Astra | Opel Astra |
| Opel Corsa | Opel Corsa |
| Opel Frontera | Isuzu MU Wizard |
| Opel Kadett | Opel Kadett |
| Opel Meriva | Opel Meriva |
| Opel Senator | Opel Senator |
| Opel Vectra | Opel Vectra |
| Opel Zafira | Opel Zafira |
| Open Directory Project | Open Directory Project |
| Open Enterprise Server | Novell Open Enterprise Server |
| Open Range | Open Range |
| Open Sound System | Open Sound System |
| Open Source Development Labs | Open Source Development Labs |
| Open University | Open University |
| OpenArena | OpenArena |
| Openbox | Openbox |
| OpenSolaris | OpenSolaris |
| OPENSTEP | OpenStep |
| OpenSUSE | OpenSUSE |
| OpenTibia | OpenTibia |
| OpenVMS | OpenVMS |
| OpenVPN | OpenVPN |
| opera | opera |
| Opera -n | Opera |
| Opera buffa | Opera buffa |
| Opera metal | Symphonic metal |
| opera- | operatic |
| operabel | operable |
| Operación Puerto | Operación Puerto doping case |
| Operaen på Holmen | Copenhagen Opera House |
| Operahuset i Sydney | Sydney Opera House |
| operation | operation |
| Operation Achilles | Operation Achilles |
| Operation Artemis | Operation Artemis |
| Operation Bagration | Operation Bagration |
| Operation Barbarossa | Operation Barbarossa |
| Operation Blå | Case Blue |
| Operation Condor | Operation Condor |
| Operation Corkscrew | Operation Corkscrew |
| Operation Desert Storm | Desert Storm |
| Operation Dragoon | Operation Dragoon |
| Operation Dynamo | Operation Dynamo |
| Operation Entebbe | Operation Entebbe |
| Operation Fenix | Phoenix Program |
| Operation Foxley | Operation Foxley |
| Operation Frühlingserwachen | Operation Frühlingserwachen |
| Operation Greif | Operation Greif |
| Operation Highjump | Operation Highjump |
| Operation Husky | Allied invasion of Sicily |
| Operation Ivy | Operation Ivy |
| Operation kjoltyg | Operation Petticoat |
| Operation Ladbroke | Operation Ladbroke |
| Operation Leo | Operation Leo |
| Operation Market Garden | Operation Market Garden |
| Operation Mars | Second Rzhev-Sychevka Offensive |
| Operation Maslenica | Operation Maslenica |
| Operation Merkur | Battle of Crete |
| Operation Mincemeat | Operation Mincemeat |
| Operation Neptune | Operation Neptune |
| Operation Nordwind | Operation Nordwind |
| Operation Northwoods | Operation Northwoods |
| Operation Overlord | Battle of Normandy |
| Operation Panzerfaust | Operation Panzerfaust |
| Operation Platinfuchs | Operation Platinum Fox |
| Operation Polarfuchs | Operation Arctic Fox |
| Operation Reinhard | Operation Reinhard |
| Operation Rösselsprung | Raid on Drvar |
| Operation Seelöwe | Operation Sealion |
| Operation Silberfuchs | Operation Silver Fox |
| Operation Sledgehammer | Operation Sledgehammer |
| Operation Stella Polaris | Operation Stella Polaris |
| Operation Storm | Operation Storm |
| Operation Tanne Ost | Operation Tanne Ost |
| Operation Tannenbaum | Operation Tannenbaum |
| Operation Tannenberg | Operation Tannenberg |
| Operation Ten-Go | Operation Ten-Go |
| Operation Torch | Operation Torch |
| Operation Vigilant Resolve | First Battle of Fallujah |
| Operation Weserübung | Operation Weserübung |
| operationer | operations |
| Operations Support System | Operations Support Systems |
| operationssal | theatre |
| Operationssystem | Operating system |
| operativsystem | operating system |
| Operativsystemkärna | Kernel |
| Operatorprioritet | Order of operations |
| operatris | operator |
| operatör | operator |
| operera | operate |
| opererande | operating |
| Opererande thetan | Operating Thetan |
| opererar | operates |
| opererbar | operable |
