- Junk Robot Computerkong
- Junk Robot Teapot Kangaroo
- Junk Servant
- Junk Synchron
- Junk Warrior
- Juragedo
- Justice Bringer
- Jutte Fighter
- KA-2 Des Scissors
- Kachi Kochi Dragon
- Kagemusha of the Blue Flame
- Kageningen
- Kagetokage
- Kaibaman
- Kairyu-Shin
- Kaiser Dragon
- Kaiser Glider
- Kaiser Sea Horse
- Kaitoptera
- Kamakiriman
- Kamion, the Timelord
- Kamionwizard
- Kazejin
- KC-1 Crayton