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)
- Lawful Neutral (2 members)
- Lawyers (2 members)
- Le-Koro (1 member)
- Le-Koro Guard (2 members)
- Le-Lesterin (1 member)
- Le-Matoran (8 members)
- Le-Toa (14 members)
- Le-Wahi (4 members)
- Le-Wahi (BZPRPG III) (2 members)
- Lesterin (12 members)
- Lesterin (BZPRPG III) (6 members)
- Lesterin (NBZP) (1 member)
- Lighning Elementals (1 member)
- Light Elementals (BZPRPG) (2 members)
- Lighting Elementals (NBZPRPG) (1 member)
- Lightning Elementals (2 members)
- Lightning Elementals (BZPRPG III) (4 members)
- Lightning Elementals (Fracture) (1 member)
- Lightning Elementals (The Gate) (2 members)
- Limbo Characters (BZPRPG III) (2 members)
- Locations (77 members)
- Locations (BZPRPG) (19 members)
- Locations (BZPRPG I) (5 members)
- Locations (BZPRPG III) (28 members)
- Locations (Bara Magna (Series)) (13 members)
- Locations (Ghosts of Bara Magna) (0 members)
- Locations (NBZP) (17 members)
- Locations (SK) (0 members)
- Lorebook (25 members)
- Lorebook: Atlas (10 members)
- Lorebook (BZPRPG III) (1 member)
- Lorebook (WIP) (14 members)
- Machine (BZPRPG) (2 members)
- Magnetism Elementals (2 members)
- Magnetism Elementals (BZPRPG) (2 members)
- Magnetism Elementals (BZPRPG I) (1 member)
- Magnetism Elementals (BZPRPG III) (5 members)
- Magnetism Elementals (NBZP) (1 member)
- Magnetism Elementals (New BZPRPG) (1 member)
- Magnum Opus (1 member)
- Maintenance Templates (18 members)
- Makuta (1 member)
- Makuta (AMG) (1 member)
- Makuta (BZPRPG) (6 members)
- Makuta (BZPRPG I) (2 members)
- Makuta (BZRPG) (1 member)
- Makuta (The Gate) (1 member)
- Makuta Generals (The Gate) (1 member)
- Makuta Miras' characters (6 members)
- Makuta Vulgaris (BK) (2 members)