The following categories exist on the wiki, and may or may not be unused. Also see wanted categories.
- Iron Man (31 members)
- JACK-5 (1 member)
- JP (7 members)
- Jack-5 (4 members)
- Jacky Bryant (2 members)
- Jagi (1 member)
- Jamie (11 members)
- Janet Cage (16 members)
- Jann Lee (2 members)
- Jax (7 members)
- Jax Briggs (2 members)
- Jhun Hoon (67 members)
- Jill (40 members)
- Jin Chonrei (2 members)
- Jin Chonshu (2 members)
- Jin Kazama (10 members)
- Jinpachi Mishima (1 member)
- JoJo's Bizarre Adventure (401 members)
- JoJo's Bizarre Adventure: Heritage for the Future (11 members)
- JoJosHFTF (6 members)
- Joe (5 members)
- Joe Higashi (49 members)
- Johann (1 member)
- Johnny Cage (3 members)
- Jojo's Bizarre Advanture: Heritage for the Future (1 member)
- Jojo's Bizarre Adventure (15 members)
- Jojo's Bizarre Adventure: Heritage for the future (1 member)
- Jojo's Bizarre Advenutre: Heritage for the Future (2 members)
- Jubei Yagyu (1 member)
- Jubei Yamada (47 members)
- Judas (2 members)
- Juli (25 members)
- Julia Chang (9 members)
- June Lin Milliam (1 member)
- Juni (25 members)
- Juri (7 members)
- Justice Gakuen (3 members)
- Justice Gakuen characters (24 members)
- K' (6 members)
- K9999 (1 member)
- Kaede (1 member)
- Kairi (1 member)
- Kameo darrius (1 member)
- Kano (2 members)
- Kano (Kameo) (4 members)
- Kano (Mortal Kombat) (2 members)
- Karasu (Ninja Master's) (117 members)
- Karin (20 members)
- Kasumi (2 members)
- Kasumi (Ninja Master's) (57 members)