The following categories exist on the wiki, and may or may not be unused. Also see wanted categories.
- Informant (1 member)
- Inns (1 member)
- Intact (Six Kingdoms (Series)) (1 member)
- Inventors (6 members)
- Iroiit (1 member)
- Iron/Darkness Elementals (BZPRPG) (1 member)
- Iron Elementals (4 members)
- Iron Elementals (BZPRPG III) (4 members)
- Iron Elementals (NBZP) (1 member)
- Iron Elementals (NBZRPG) (1 member)
- Iron Tribe (2 members)
- Island Liberation Squad (18 members)
- Island Metropoliss (BZPRPG) (1 member)
- Islands (6 members)
- Islands (BZPRPG) (1 member)
- Islands (BZPRPG III) (3 members)
- It, but is referred as a male. Characters (Bionicle Kingdoms III-IV) (1 member)
- Items (NBZP) (2 members)
- Jakura Nuva's Characters (13 members)
- Jaliax Sister (3 members)
- Jargon (1 member)
- Journalists (4 members)
- Jungle Tribe (2 members)
- Kalama's Raiders (11 members)
- Kale Roho (NBZP) (1 member)
- Kanohi (9 members)
- Kanohi (BZPRPG III) (2 members)
- Kanohis (1 member)
- Kanohis (BZPRPG III) (5 members)
- Kentoku Archipelago (15 members)
- Kentoku Archipelago (BZPRPG III) (2 members)
- Kin (BZPRPG) (2 members)
- Kin Storyline (BZPRPG) (2 members)
- Kinetics Elementals (BZPRPG) (1 member)
- Ko-Koro (1 member)
- Ko-Koro (BZPRPG III) (2 members)
- Ko-Koro Guard (2 members)
- Ko-Matoran (8 members)
- Ko-Skakdi (3 members)
- Ko-Toa (11 members)
- Ko-Wahi (10 members)
- Ko-Wahi (BZPRPG III) (4 members)
- Kru-Toa (3 members)
- Kumu-Islets (3 members)
- Lag (1 member)
- Lasers Elementals (BZPRPG) (1 member)
- Law Enforcement (BZPRPG III) (7 members)
- Law Enforcements (BZPRPG III) (1 member)
- Lawful Evil (2 members)
- Lawful Good (18 members)