| keyhelp | Zoom Player Keyboard Macros Data |
| keylist | Zoom Player Virtual Keyboard Layout |
| keyring | Java Key Store |
| keystore | Java Key Store |
| kez | CA 01 Customer Product Numbers Data |
| kfl | Kwalitan Filter Data |
| kfo | Konica Minolta Bizhub Copier Overlay Data |
| kfr | Kalles Fraktaler 2 Data |
| kfx | Kofax Capabilities File |
| kgf | UniCERT Key Generation Data |
| kgm | KeyTERRA-FIRMA Ground Model Data |
| kgs | Kogeo Session Data |
| kgtemp | KuGou Temporary Cache Data |
| kh | Khmer-Protocols Hash Table |
| khd | Microsoft Dynamics AX Kernel Help Documentation |
| khf | Kwalitan Tree Structure |
| khs | Kwalitan History Data |
| khub | Offline Course Player Data |
| kids | SAM Kestrel Sequence Id Data |
| kim | Commodore KIM-1 Image |
| kip | OA-KIP Client Data Transfer File |
| kipf | Kemper Profiler Presets Data |
| kipr | Kemper Profiler Profile Data |
| kipx | QQ Messenger Theme Data |
| kir | Kiruna Magnetometer Data |
| kismac | KisMAC Webservice |
| kiwi | KiwiViewer Scene |
| kjb | Kettle Job File |
| kjv | theWord King James Version Module |
| kkk | Filmetrics F20 Material Data |
| kkw | Adobe RoboHelp Keyword Help Project Index |
| klb | KidPix Stamp Album |
| klf | KaloMa Data File |
| kli | WUFI Climate Data |
| klip | KlipFolio Klip |