The following categories exist on the wiki, and may or may not be unused. Also see wanted categories.
- Nintendo (1 member)
- Nintendo 3DS games by name (1 member)
- Nintendo 64 (1 member)
- Nintendo Switch games by name (2 members)
- Nintendo consoles (2 members)
- Nintendo hardware (1 member)
- Noindexed pages (2 members)
- Non-sporting breeds (1 member)
- Number 64 on objects (1 member)
- Nuvola 2.0+ icons (1 member)
- Nuvola 2.0+ icons needing conversion to SVG (0 members)
- Nuvola PNG icons (1 member)
- Nuvola icons (1 member)
- Observation (1 member)
- One-letter templates (1 member)
- Online games (1 member)
- Open-world video games by name (1 member)
- OpenGL (1 member)
- Optical device icons (1 member)
- Orders of Mammalia (1 member)
- Orders of Synapsida (1 member)
- Otariidae (1 member)
- Otariinae (0 members)
- PD ineligible (1 member)
- PD license tags (1 member)
- PD shape (1 member)
- Page TOC templates (1 member)
- Pages using "Collapse" template without content (1 member)
- Pages using the JsonConfig extension (89 members)
- Pages with TemplateStyles errors (1 member)
- Pages with broken file links (19 members)
- Pages with incorrect biology template usage (7 members)
- Pages with incorrect template usage (1 member)
- Pages with invalid language codes (1 member)
- Pages with script errors (15 members)
- Paranormal (1 member)
- Phenomena (1 member)
- Philosophical concepts by field (1 member)
- Pinnipedia (0 members)
- Pinnipediformes (1 member)
- Placentalia (1 member)
- Plant-based food (1 member)
- PlayStation 3 games by name (1 member)
- PlayStation 4 games by name (2 members)
- PlayStation Vita games by name (1 member)
- PowerPC game consoles (1 member)
- Primary license tags (flat list) (2 members)
- Processes (1 member)
- Products by name (1 member)
- Proprietary emulation software (1 member)