K
| Class | Country | Type | Launch years | Displacement (tons) | Number |
| Kagero | Japan | destroyer | 1938-41 | 2,033 | 18 |
| Kamikawa Maru | Japan | seaplane tender | 6,863 | 4 | |
| Kamikaze | Japan | destroyer | 1922-25 | 1,400 | 9 |
| Kashii Maru | Japan | armed merchant cruiser | 1934-41 | 8,600 | 5 |
| Katori | Japan | light cruiser | 1939-40 | 6,280 tons | 4 (3 completed) |
| Kent | UK | heavy cruiser | 1926-27 | 9,850-10,900 | 7 |
| King George V | UK | battleship | 1939-40 | 36,727 | 5 |
| Kirov | USSR | cruiser | 1938-40 | 7,756 | 2 |
| Kondouritis | Greece | destroyer | 1931-32 | 1,389 | 4 |
| Kongo | Japan | battleship | 1912-13 | 31,720 | 4 |
| Königsberg = K | Germany | light cruiser | 1927-28 | 6,650 | 3 |
| Kuha | Finland | minesweeper | 18 | 6 | |
| Kuma | Japan | light cruiser | 1919-20 | 5,019 | 5 |
| Kyzikos | Greece | torpedoboat | 1914-15 | 270 | 3 |
Read more about this topic: List Of World War II Ship Classes