Pai
- Addison's disease
- African Independence Party
- Bad Gyal
- Bae (surname)
- Gwat Pai
- Italian African Police
- Northern Sotho
- PAI Partners
- Pai (Chinese surname)
- Pai (Manga character)
- Pai (fish trap)
- Pai (surname)
- Pai Airport
- Pai District
- Pai Gow
- Pai Northern Thai Kitchen
- Pai River
- Pai gow poker
- Pai languages
- Pai, Iran
- Pai, Tank
- Pai, Thailand
- Parachute Association of Ireland
- PartnerAid
- Partnership on AI
- Pathogenicity island
- Periodic annual increment
- Persatuan Arab Indonesia
- Personality Assessment Inventory
- Photoacoustic imaging
- Pie (Tokyo Mew Mew)
- Plasminogen activator inhibitor-1
- Plasminogen activator inhibitor-2
- Poalei Agudat Yisrael
- Polyamide-imide
- Polyatomic ion
- Population Action International
- Public Accountability Initiative
- Ulrik Wisløff