| opalskimrande | opaliserend |
| opartisk | zuiver |
| opassande | onbeschaamd |
| opassande beteende | onfatsoenlijkheid |
| opassande förslag | oneerbaar voorstel |
| Opatija | Opatija |
| OPEC | OPEC |
| Opel | Opel |
| Opel Antara | Opel Antara |
| Opel Astra | Opel Astra |
| Opel Corsa | Opel Corsa |
| Opel Frontera | Opel Frontera |
| Opel Kadett | Opel Kadett |
| Opel Meriva | Opel Meriva |
| Opel Vectra | Opel Vectra |
| Opel Zafira | Opel Zafira |
| Open Directory Project | Open Directory Project |
| Open Shortest Path First | Open Shortest Path First |
| Open Source Development Labs | OSDL |
| Open Systems Interconnection | OSI-model |
| Open University | Open University |
| OpenArena | OpenArena |
| OpenSolaris | OpenSolaris |
| OpenVMS | OpenVMS |
| Opera buffa | Opera buffa |
| Opera metal | Symfonische metal |
| opera- | opera- |
| operabel | operabel |
| Operación Puerto | Operación Puerto |
| Operaen på Holmen | Operagebouw van Kopenhagen |
| Operahuset i Sydney | Sydney Opera House |
| operation | operatie |
| Operation Barbarossa | Operatie Barbarossa |
| Operation Blå | Operatie Fall Blau |
| Operation Condor | Operatie Condor |
| Operation Dragoon | Operatie Dragoon |
| Operation Dynamo | Operatie Dynamo |
| Operation Flashpoint | Operation Flashpoint |
| Operation Greif | Operatie Greif |
| Operation Husky | Landing op Sicilië |
| Operation Ivy | Operation Ivy |
| Operation Market Garden | Operatie Market Garden |
| Operation Merkur | Landing op Kreta |
| Operation Overlord | Landing in Normandië |
| Operation Polarfuchs | Operatie Polarfuchs |
| Operation Reinhard | Aktion Reinhard |
| Operation Seelöwe | Operatie Seelöwe |
| Operation Sledgehammer | Operatie Sledgehammer |
| Operation Sommarregn | Operatie Zomerregens |
| Operation Storm | Operatie Storm |
| Operation Torch | Operatie Toorts |
| Operation Weserübung | Operatie Weserübung |
| Operationsförstärkare | Operationele versterker |
| operationssal | operatiekamer |
| operativsystem | besturingssysteem |
| Operativsystemkärna | Kernel |
| Operator | Operator |
| Operatorprioritet | Rekenregel |
| operera | opereren |
| opererbar | operabel |
| opersonlig | onpersoonlijk |
| Opex | Opex |
| Ophelia | Ophelia |
| opiat | opiaat |
| Opievallmo | Slaapbol |
| opium | opium |
| Opiumkrigen | Opiumoorlog |
| Opkonst | Op-art |
| oplanerad | toevallig |
| Oplotnica | Oplotnica |
| Opole | Opole |
| Opole vojvodskap | Opole |
| opolerad | grof |
| opolitisk | onpolitiek |
