| Operating chart | Organisatieschema |
| operating expenses | exploitatiekosten |
| operating system | besturingssysteem |
| Operating system shell | Shell van besturingssysteem |
| operation | activiteit |
| Operation Alsos | Jacht op het Duits atoomwapen in WOII |
| Operation Amherst | Operatie Amherst |
| Operation Anthropoid | Operatie Anthropoid |
| Operation Arctic Fox | Operatie Polarfuchs |
| Operation Auca | Operatie Auca |
| Operation Autumn Clouds | Operatie Herfstwolken |
| Operation Barbarossa | Operatie Barbarossa |
| Operation Barbarrosa | Operatie Barbarossa |
| Operation Battleaxe | Operatie Battleaxe |
| Operation Biting | Bruneval Raid |
| Operation Bluecoat | Operatie Bluecoat |
| Operation Brevity | Operatie Brevity |
| Operation Chastise | Operatie Chastise |
| Operation Cobra | Operatie Cobra |
| Operation Condor | Operatie Condor |
| Operation Crusader | Operatie Crusader |
| Operation Days of Penitence | Operatie Dagen van Boetedoening |
| Operation Dragoon | Operatie Dragoon |
| Operation Dynamo | Operatie Dynamo |
| Operation Fall Rot | Operatie Fall Rot |
| Operation Fortitude | Operatie Fortitude |
| Operation Gladio | Operatie Gladio |
| Operation Greif | Operatie Greif |
| Operation Herbstreise | Operatie Herbstreise |
| Operation Herkules | Hercules |
| Operation Himmler | Operatie Himmler |
| Operation Ivy | Operation Ivy |
| Operation Lüttich | Operatie Lüttich |
| Operation Market Garden | Operatie Market Garden |
| Operation Mobilisation | Operatie Mobilisatie |
| Operation Neptune | Landing in Normandië |
| Operation Paget | Operation Paget |
| Operation Plunder | Operatie Plunder |
| Operation Pluto | Operatie Pluto |
| Operation Reinhard | Aktion Reinhard |
| Operation Sealion | Operatie Seelöwe |
| Operation Shingle | Landing bij Anzio |
| Operation Sledgehammer | Operatie Sledgehammer |
| Operation Storm | Operatie Storm |
| Operation Torch | Operatie Toorts |
| Operation Typhoon | Operatie Typhoon |
| Operation Uranus | Operatie Uranus |
| Operation Walküre | Operatie Walküre |
| Operation Weserübung | Operatie Weserübung |
| Operation Wrath of God | Caesarea |
| operational | operationeel |
| Operational definition | Instrumentalisme |
