Encyclopedias, Almanacs, Transcripts, and Maps
- papal infallibility
- Parables and Proverbs
- Paradox and Riddles
- Paralympic Games
- Paramārtha
- Pāramitās
- Pardalotes (Pardalotidae)
- Parentalia
- Pareto Optimality (Maximum Social Welfare)
- Paris, Treaties of
- Parmigiano
- Parnassus
- Parrots and Parakeets
- Parsley Frogs (Pelodytidae)
- Parsons, Charles Algernon (1854–1931)
- Particulate
- Partnership for Pollution Prevention
- Parts per Billion
- Parts per Million
- Parts per Trillion