| 40947 | Klong | ZX81 16K | English |
| 39347 | Kludo | ZX81 16K | English |
| 44084 | Kludo + Battleships | ZX81 16K | English |
| 40465 | Knight's Move | ZX81 16K | English |
| 36784 | Knights & Demons | ZX81 16K | English |
| 29016 | Knikkers | ZX81 16K | Dutch |
| 29551 | Knitting Pattern | ZX81 16K | English |
| 40578 | Knockout Fred and the Circlemen | ZX81 16K | English |
| 29017 | Knoop | ZX81 16K | Dutch |
| 29018 | Kolenmijn | ZX81 16K | Dutch |
| 33425 | Kong | ZX81 16K | - |
| 41449 | Kong Jump | ZX81 16K | English |
| 40952 | Kong Leap | ZX81 16K | English |
| 31701 | Kongs Revenge | ZX81 16K | - |
| 29020 | Kosten | ZX81 16K | Dutch |
| 31702 | Krakit | ZX81 16K | - |
| 31703 | Krakit Demo | ZX81 16K | - |
| 29024 | Krazy Kong | ZX81 16K | English |
| 44512 | Krazy Kong | ZX81 16K | English |
| 31943 | Krazy Kong - Chroma Edition | ZX81 16K | English |