Term | Explanation |
| Kempei | Japanese military police. |
| Knickebein | Crooked Leg - German navigational system using radio beams to guide bombers. |
| Kondor Mission | German espionage operation based in Egypt. |
| Konstantin | Operational code name for the German occupation of the Balkans areas previously occupied by Italian forces - September 1943. |
| Kriegsmarine | The German Navy. |
| Kripo | Kriminalpolizei - German criminal police department. |
| Kutusov | Operational code name for the Soviet offensive against German forces in the Kursk Salient - July 1943. |